When lines get blurred... Please help!

I had an interesting nightmare last night, or perhaps it was this morning. I was running away from a high school teacher I don’t want anything to do with anymore, and when we finally ran into each other, all we could do is glare – he for his own reasons, I for mine. And of course he’s much more taller than me, reinforcing how we literally and figuratively don’t see eye to eye.

We used to talk online and it was alright. We talked to each other like we did when I was a sophomore and he was my sophomore biology teacher. Sometimes we joked about certain things that aren’t quite typical of a student/teacher relationship, but it was more or less innocuous. But then he started to realize that we are both adults and he wanted to swing our relationship in a direction I was very hesitant of going; it was a very subtle shift (he didn’t say anything about it directly, but our conversations – more on his side – were . . . raunchier?). I tried to ignore it for a while, but he kept pressing in that direction and suddenly I snapped and my defenses locked in and I started avoiding him online, and then just this August, I blocked him on AIM.

All these lines are getting blurred and some are just downright going away, and I don’t like it. Whatever happened to the student remaining the student and the teacher/professor remaining the . . . well, the teacher?

That’s why I don’t want to be associated with him anymore, because a long time ago, he violated (and still continues to) our student/teacher relationship with a behavior that wasn’t suited for it. I tried to live with it, and forgive him, but I couldn’t. And now I can’t even face him for two minutes to tell him that I don’t want to deal with him anymore. I know it’s a terrible thing to be so avoidant, and he’s probably worrying himself silly about what he’s done and that’s the thing I can’t forgive:

What don’t you understand about what you’ve done?

I don’t know what to do! Is there anything that should even be done?