I was sexually abused when I was 9 years old. It went on for three years.

I am now 17 and reliving this abuse in my nightmares. I've been having them for three months now and am scared to go to sleep at night.

I first thought it was my fault, then I blamed it on my father's drinking problem. Now I don't know what to think any more.

It affects my home life, my schooling and my relationships with guys. It's the emotional part I can't seem to handle so well. Physically I look fine, but sometimes I think I'm going crazy.

My school counselor has advised me to see a therapist. We've called places that are supposed to give people this kind of help in my township and they all said they'd call me back for an appointment. It has been two weeks now, calling back and forth. What should I do?

Keep calling, dear. And have your school counselor call the people in charge at each of these places and put them on the spot. Sometimes it takes a word from the boss to make things happen. And they should happen as soon as possible.

The Family Services Association may be able to provide you with immediate attention or arrange an appropriate referral if you tell them it's an emergency. And it is.

You've been brave for years, but your delayed reaction tells you it's time to get help.

Your depression (for that's what it is) is serious, classic, understandable, inevitable -- and fixable. Some degree of depression is also not that unusual at your age, for this is the time when the mind catches up with the body. A person begins to think in abstractions between 14 and 16 and then the conscience comes fully alive. This can make her look back in dismay at certain events in her past and feel a sense of worthlessness.

You cannot tell yourself often enough: What happened was NOT your fault. It's almost impossible for a preteen to resist the advances of someone she knows and trusts.

You must realize that this is true, but the realization alone won't make the guilt, the sorrow and the nightmares go away. You must have professional counseling as soon as possible to unload the freight that wears you down.

Therapy will teach you that you can live with your past as well as your future; that the courage you've shown already will give you still more; and that, with help, all problems have solutions. They may not be perfect (they seldom are) but you'll survive well if you concentrate on the pluses.

Your therapist also could arrange professional help for your father, which he needs so badly, although it may not be enough.

In addition, she will consider, with your help, whether to call in the authorities, even though this abuse ended six years ago. If you have a little sister at home, or if your father works with children, either professionally or as a volunteer, they could be at risk. A person who would molest one child usually will molest another, if the circumstances make it easy or if he drinks too much. Alcohol can remove the most basic inhibitions and often plays a part in child abuse, particularly sexual abuse. It probably played a significant role in your father's behavior toward you.

Even if alcohol isn't still a problem in your home, you'll profit by attending weekly meetings of Alateen, listed under Al-Anon in the phone book. You won't have to say anything at the meetings except give your first name and even that isn't mandatory.

At these meetings you'll learn how alcoholism works; how a physical disease can have emotional symptoms -- and tragic results -- for both the alcoholic and the child and how other teen-agers are coping. Your father betrayed your trust so profoundly that it will be hard for you to rely on him again, but in time you might develop enough compassion to wish him well.

Once you've wept over your losses, you'll be able to put a new world together -- as all high school graduates must do -- and you can decide what kind of world it will be. Your friends will be the heart of it. Choose them carefully, for they will be your new family. Be true to them, help them, defend them, enjoy them and forge binds so tight you'll know they'll be there for you, just as you are for them. By concentrating on friendships, with both boys and girls, you'll find a committed romantic relationship will evolve naturally.

And to keep you from feeling so alone in the meantime, read Early Sorrow: Ten Stories of Youth, edited by Charlotte Zolotow (Harper & Row; $12.70). This splendid collection of short stories will remind you that the tragedies of life can help you grow. Questions may be sent to P.O. Box 15310, Washington, D.C. 20003. Worth Noting

A second edition of the first-rate Preschool & Daycare Book by Merry Cavanaugh, with more than 200 in-depth descriptions of programs in the Washington metropolitan area, 620 other listings and much good advice. At local bookstores, toy stores and children's clothing stores for $7.95.