For weeks, newlyweds Darrell Beschen and Beverly Geserick had been sitting nervously in different offices at the Department of Energy awaiting final word on the employment shakeup at their beleaguered agency.

Then, a week ago Friday, it all began to unravel. First, Beschen, 34, received the bittersweet news that he was being kept on, at two grade levels lower and in an entirely unrelated job in his wife's department. Two hours later, his wife, 29, got her walking papers.

And finally on Thursday night, the eve of her dismissal, Geserick and her husband heard President Reagan outline new budget cuts that could put both of them out of work.

"There's so much stress and uncertainty that we're sort of cheated out of the glow of being newly married," says Beschen, reflecting on the four months of their marriage. "I mean, there were a lot of contingencies we planned for, but this wasn't one of them."

After months of speculation and anxiety, the budget ax has fallen on thousands of federal workers like Beschen and Geserick. Nearly 6,000 will have been officially "separated" from their government jobs as of Wednesday, with the vast majority of those dismissals coming in these last few days of the fiscal year. Countless others are taking demotions just to hang onto their government pay checks.

And what has happened to those workers will be in store for 75,000 others if Reagan succeeds in his new reduction in force (RIF) goals.

The actual number of layoffs in this first round of RIFs will be less than initially forecast for the fiscal year -- about 5,883 nationwide, including about 2,500 here, compared to an earlier estimate of 15,000, according to the Office of Personnel Management. But the months ahead will see a sharp rise in government dismissals, with some 6,000 set for the Department of Health and Human Services alone by the end of October.

The whole process "really has created a lot of anguish," says J. Michael Power, a director of policy, planning and evaluation at DOE's conservation and renewable energy office, Beschen and Geserick's division. Power has particular sympathy for the people who joined federal service because they viewed it as a calling or believed in a certain program.

"Now they're told that what they were doing wasn't important, that it was a waste of the public's money," says Power, who this past week found himself signing "outstanding" government performance ratings for employes being forced out the door.

"It's the most poignant illustration of the bureaucracy and very painful," Power says.

Some examples:

John Macomber, 67, is unhappily retiring after 23 years as a government employe. Barring court intervention, his job and some 950 others will be abolished at the soon-to-be defunct Community Services Administration. He has decided to move to North Carolina, to live more cheaply, but so far he has been unable to sell his house here.

"I've never been in such a bind in my whole life," said Macomber, who thought he had sold him home this past June until the prospective buyer lost his job, too.

Beschen and Geserick, at the Department of Energy, thought for a brief time last week that he had "bumped" her -- a term used when one worker with more seniority and other retention rights takes the position of another. That's what Geserick was initially told by her boss.

Beschen is moving into his wife's section but not into her job. An economist by training and a GS 14 program manager, he will now be a GS 12 in the weatherization office. "I had to tell them whether I would accept the job even before I could find out for sure what the job was," he complains.

Catherine Taber, 36, has survived the first round of RIFs at her agency, the Commerce Department, but now finds herself doing very different work. She was a GS 12 editor for internal publications; now she's a GS 8 secretary.

"I'd just been given more duties in May, and then a few weeks later I got the notice I was being RIFed," said Taber, a government employe for 10 years. "Now I do the typing for three professionals and an intern, organize the files and answer the phones."

Archie Twitchell, 46, ended his job at the Department of Energy yesterday. He had worked for the government for three years, most recently as a GS 14 in charge of the agency program overseeing building energy performance standards.

"My wife is working but this will still mean a dramatic change in life style," said Twitchell, who so far has turned up few job prospects. He calls the RIFs needless and views them as a mean-spirited way to "punish the people in the bureaucracy." Most of all, he worries about "the energy programs that aren't being done."

OPM has collected data from each of the agencies about the number of separations expected for this fiscal year, but Reg Jones, who chairs the government's task force on personnel reductions, cautions that the numbers will keep changing right up until Sept. 30, depending on how many employes accept reassignments or decide to leave.

Statistics on the number of downgradings are not being kept by OPM, although a congressional task force is currently surveying the agencies to determine separations and demotions as well as the impact of the RIFs on blacks and women.

In the Department of Energy, for example, the conservation and renewable energy office is expected to separate about 100 or more workers nationwide and demote another 219. Downgradings there are averaging about two levels per employe, although about 40 people have been demoted three to seven levels. Some of those experiencing the severest downgradings have complained that DOE relied on outdated job descriptions in deciding who would be reassigned where.

At the Department of Transportation, some 923 positions have been abolished nationwide as of this week, resulting in 522 separations and 180 demotions. At the Commerce Department, a spokesman there knew only that about 450 workers have been RIFed so far but he could not provide figures on separations versus demotions.

Under Civil Service protections, an employe who is downgraded retains his or her old salary level for two years. This gives workers what one employe calls a "breathing spell" and an opportunity to keep jobs in government while they look for another. Employes nearing retirement are also apt to stay on, even if it means a drastic shift in their working arrangements.

"I have 19 years in and it's to my benefit to hang on," said one government worker who had just learned she will be downgraded from a GS 11 administrator to a GS 5 secretary. "When I think of how I went to night school and everything else to improve myself . . . ."

At the Department of Energy, some employes are compiling a "sunset report" so history will have a record of accomplishments in sections that are being shut down. At the Community Services Administration, the old War on Poverty agency founded by president Lyndon Johnson, employes plan to hold a wake in the streets Wednesday and have thrown out reams of material they expect no one will want to look at again.

And at HHS, where severe RIFs are still ahead next month, employes at the Alcohol, Drug Abuse and Mental Health Administration had organized themselves into an ad hoc group six months ago and recently raised $3,000 for exploratory legal work in preparation for possible court action to fight the reductions.

But throughout the government, workers' waning days have been dominated by job hunting. Agencies have had mixed success in finding other government work for displaced employes, although OPM efforts have picked up somewhat. Nationally, 833 workers registered with the Voluntary Interagency Placement Program have been placed in new jobs as of mid-September, most of them with the government. Locally, VIPP and OPM's displaced employes program have placed a total of 47 and made more than 2,100 referrals.

At this point it is difficult to predict where the RIFed employes will end up. But the evidence of where they aren't can be found all over town.

"You have reached a nonworking number at the White House . . . call a White House operator . . . " a recorded voice advises those who try to call the abolished Council on Wage and Price Stability, which once employed a staff of 170.

And at many agencies the oft-heard response to requests to speak to a certain employe is: "She or he doesn't work here anymore."