When Armando walked into an American supermarket for the first time in his life, he felt a terible nausea. In his entire adult life in Cuba, he had never seen such abundance.

In the Revolution, austerity had been made into a virtue, an end in itself. "It hit me all at once," said Armando. "Cubans have lived for so long on so little. And for that little we stood in line like beggars. Here suddenly was too much of everything. Forgive me, but it seemed grotesque."

Four months ago, Armando Ramirez and his family were practically barricaded inside their modest home in Vedado, a popular Havana neighborhood. Outside, a furious crowd of neighbors was hurling stones, eggs and insults at this family of model revolutionaries who had abruptly taken off their masks and said they wanted to emigrate to the United States.

The Ramirez family spent 11 insufferable days of asylum, with 10,000 others, in the stench of the Peruvian embassy. Later they waited at home, through sleepless nights, for a knock on the door, for word they could board a refugee boat.

It came at midnight, late in May, as a state security officer told Armando: "You have five minutes to prepare yourself." When Armando replied he could not leave without his wife and two teen-age sons, who also held exit documents, the officer told him: "We're going. You can choose. Either you leave the country or you go to jail."

Now he is living in Miami and, like thousands of other Cuban refugees, trying to deal with the political and cultural shock of life in the United States.

The move from the regimented, protective, paternalistic world of communism into the do-it-yourself, at-your-own-risk, open society of capitalism was far more difficult than he expected. He and some of his friends had dreamed of "American freedom" for more than eight years, yet now they had trouble using it or coping with it.

Statistically, Armando Ramirez, who asked that his real name not be used to protect his family, is considered a success. In the federal refugee files he is registered, he said, as a man with a sponsor, a home and a job.

Yet he has been thrown out by his sponsor -- his brother -- and for his part-time job as a handyman he settles for less than half the legal minimum wage. With six other refugees, he has rented a two-room apartment.There is no furniture, just a few mattresses on the floor and $65 worth of food stamps per person per month.

All this bothers Armando less than his daily fight against depression and deep guilt feelings about leaving his family behind.

"The government played a terrible vengeance on people like me. I'm not the only one forced into separation," he said.

Gloria, his wife, had insisted that night that he leave the country, rather than go to jail. Rogerio, his elder son, whom he worships, was not at home when Armando dropped out of his life.

Armando believes he made the right decision and would not return to Cuba if he had the chance. But since the day he boarded the old, overloaded shrimp boat that hung dangerously deep in the water for 36 hours, he says he has lived in a daze. He has lost weight and gained dark circles under his eyes.

He and his roommates have discovered "the constant need for money." They will get evicted from the apartment if they do not pay the rent on time. The telephone will be cut off if the bill is not paid. His temporary job, in a refugee-swollen market, may last only weeks, so he works anxiously on Saturdays and Sundays as well. All these uncertainties never existed in his predictable communist world, he said.

He cannot get used to the lavishness, the wealth and waste in some parts of Miami that exist side by side with the meager life in the black neighborhoods. "There were differences in Cuba," he said, "but never such extremes."

A 44-year-old former radio technician, he is bewildered by the American system. Coming from a society where everything is constantly subject to Marxist political discussion, he finds the average American politically uneducated, or curiously apolitical.

"In Cuba I was living in a world where the answers were simple. I had understood communism and its injustices. I knew it had achieved a lot for Cuba. But the price was too high," he explained. "In exchange for basic security you had to be depersonalized, give up your mind. You had to pay blind homage to the system and to Fidel Castro."

Now he says he is beginning to understand "the injustices of capitalism, better than I ever did in my classes of Marxism. There are many, and they are terrible. The legal wage is $3.50 per hour, I get $1.50, some people get $1.00 I'm told. There is more injustice despite the freedom. I'm confused. There must be another road, but what?"

Although he himself is not as outgoing as many Latins, what disturbs him most, he said, is "the indifference with which people treat each other. They are like machines. It must be something the system does to them. I haven't understood this yet."

Other Cuban refugees have remarked on the indifference they say they find among the old-time Cuban refugees. While thousands of Cubans who came in the early '60s have put up refugees in their homes in the communities of Sweetwater, Hialeah and Homestead near here, refugee officials say that many old-timers see the newcomers as a threat to their stability.

There is a 20-year cultural and philosophical gap between the two groups of Cubans that even family ties or moral obligations apparently cannot bridge easily.

In July, for example, Armando moved in with his brother, who had arrived in the United States in 1962. A Miami taxi driver, he lives better than Armando ever did as a Cuban technician.

After a few painful weeks, it was clear the alliance would not work. "I did not recognize my brother. I'm sure he feels the same about me. We had nothing to say to each other."

One day his sister-in-law broke the silence. "I was a burden, I was eating too much, using all their things. She said: 'You should know that in the U.S. life is different, here it's everyone for himself.'" That day he left their house.

During a talk one night with Armando's new roommates, the four men present said that most of all they had been shocked by American attitudes toward male homosexuals. In Cuba, homosexuality is frequently punished with a prison sentence and rarely, if at all, openly discussed.

While spending time at Fort McCoy, Wis., after arriving from Cuba, they said they had been stunned by the tolerance of the American military. "Many of the Cuban ex-prisoners had become homosexuals in jail. The first weeks there were waves of marriages among them," said one man who had spent 39 days at McCoy. "Every day there were at least two or three homosexual weddings in the camp."

"With the bedsheets they made wedding dresses, very clever. They used toilet paper to make garlands and flowers for their head," replied Armando, who was there for five weeks. "There were special honeymoon quarters, those were bunkbeds separated with sheets for privacy. The American soldiers just stood around and laughed. It was incredible."

Now that he is here to stay, Armando is determined to push until he gets Gloria and his two sons to Miami.

Despite the recent closing of Mariel Harbor, point of departure for the refugee flotila, he believes his chances may not be too bad. Before he left Mariel, he had asked a government official for help in getting his family out. m

If the family has a house that would become empty, the official had whispered, their chances would improve considerably. Given the housing shortage, this is a strong negotiating point.

A few weeks ago, Armando telephoned Gloria, who had had no income or ration book since Armando left. 'She sounded terrible.Like someone on a sinking ship sending an SOS" Armando said. "I'm working hard," he told her, "I'll try and send money. But don't move in with any relatives. Whatever you do, you hold on to the house."