Inkblot...
What you are describing has happened to many women when they were vulnerable, myself included. It happened to me almost exactly as you described, when I was an awkward and insecure adolescent who just wanted to be liked, and when I was going throught my divorce and was easy prey. And like you, I didn't tell anyone about it either. I felt guilty and responsible and... just generally weak and used.

The time to change is now. Don't stress about the past -- you can't change it. But you can resolve to take no more %#@&#! from anybody.

On another note, I had a dream about you last night! Only you're not going to like this... you had really short hair, were very pretty, but had a .... full mustache and beard!

No, I don't have a clue what that means, either!