With the sleeves of his yellow sports shirt rolled up and the collar open. Dan Tobin, senior at Walt Whitman High School and spokesman for Montgomery County's student councils, stood tensley at the lectern with one foot placed on top of the other.

He was talking about the guilt he says he and other Montgomery County youth feel.

"Montgomery County is a very affluent society. Often we feel guilty because we enjoy the wealth of our parentsand we in no way contribute to the family income.

"We believe we are basically considered a nuisance to our community."

Tobin was one of several student speakers at a county-sponsored hearing on youth last week to voice concern over the "feeling of uselessness" among the teen-agers of Montgomery County.

This many youths said, coupled with excessive pressure from parents to achieve, is forcing them into an early abrupt maturity they say they feel unequipped handle. "We feel we have lost the opportunity for childhood," said one youth.

The county government began last week holding a unique series of hearings on youth that, when complete, will have given parents, youth agency officials, teachers and the youngsters themselves a chance to voice their opinions about youth problems and offer possible solutions.

"The end goal is to take a look at where we're spending money and see if we have to reorder priorities and place emphasis on new acreas," said County Executive James P. Gleason, who is personally chairing the hearings.

Youth problems are amoung the issues being investigated by a special task force Gleason set up last October to study ways in which the county can provide better services to certain sectors of its population, such as the elderly, the handicapped and the young.

While many of the youths voiced concern over the breakdown of families, either through divorce or separation, the parents, who gave their views at a hearing yesterday, concentrated on the need for more county services for youth and complained about the bureaucracy they faced when trying to get help for their children.

Among the parent's requests were that the county providemore vocational training more counseling services more facilities for after school activities, more drug programs and better transportation to get youngsters to and from activities.

One parent suggested that there be a county ombudsman to direct parents where to go for help their children.

"Parents who have been tossed about from agency to agency have said there's got to be a better way," Sandra King Shaw,president of the Montgomery Council of PTAs, told the county executive and County Council members yesterday.

A county woman said that four years ago, she attempted to find private counseling, then a community counseling agency to get help for her son, who had a drinking and drug problem. After several trips to juvenile court, she said her son was sent to Karma Academy, a highly structured therapy and education facility.

That was after a year and a half of sessions with various psychiatrists, counselors and court officials who always asked the same question, "what seems to be the problem?" she said.

Many of the parents stressed the need for "preventive services" that would identify a child's particular problems - a learning disability or mental retardation, for example - early in the child's life.

Some parents criticized the schools for not teaching youths "moral values." In sex education courses, complained Mary E. Stevens of Wheaton, "Where is the explanation of fetal development . . . where is there counseling to the dangers of abortion?"

While the parents looked to the county government for aid in coping with their children, the youngsters portrayed their parents as the source of much of their turmoil.

"Too much emphasis is placed on grades," said David Naimon, a Northwood High School senior. When a youngster can't make the grades his or her parents would like, "This leads to a feeling of inadequacy - and a lot of cheating," Naimon told the council.

"My parents give me hell when I get a "C," said Dan Tobin in an interview. "With the kids in Montgomery County, their parents have reached a high level of success, so they want their kids to do as well."

With most of the material benefits they want and need provided for them, many of the youngsters said they are not asked by their parents to get after-school jobs and they claim they are faced with finding alternatives to their boredom. Often this boredom reaches over into their school life, the students said.

"Students who are bored with school need only be taught something more relevant to their future," said Eliot Sennett of Albert Einstein High School.

Mike Raugh of Poolesville High School said he saw "a definite need for accelerated courses" for some high school students when he was placed in a first-year Spanish class because of his age, although he had already had three years of Spanish in a New York school. "Students are taking it in faster than the teachers like to give it out."

Time on their hands means time to think about problems, said Randee Bernstein of Charles W. Woodward High School, where last week, a 17-year-old senior committed suicide on the school grounds.

"I think it is essential for this matter to be brought to the attention of the county because it is important to realize that even in affluent Montgomery County definite problems such as this (suicide) do exist. We have more free time to think about our problems. Ours is not a question of survival but a filling empty time.

Several of the youths said they were concerned abouts the rising number of broken homes in the county.

"About one-third of my friends have parents who are either divorced, separated or in the process of getting divorced or separated. Another third have serious enough problems at home that it affects their psychological health," said Chris Orsinger of Winston Churchill HIgh School.

Caroline Trimble, of Rockville High, who wore saddle shoes and the school's red, white and black cheer leader's outfit to the hearing, saw some glimmer of hope for Montgomery families in the coming of Metro to the county.

"You might ask what Metro has to do with the problem. If working parents could leave later in the morning, and come home earlier inthe evening, it would at least put them physically in the house."