Boy advice needed, help?

I am a high-school student having problems with her crush. Cringe.

I like this guy (lets call him 'A'). A few months ago he used to like me but I didn't return the feelings as I liked someone else (guy 'B'). When I eventually got over B, because he was a total idiot, I started getting feelings for A. Obviously I did what teen girls do and texted my friends all about it, which eventually opened an opportunity to text A himself. We texted a little, talking about school and whatnot but it ended after a while then we never texted again.

We used to talk in real life, but now that we both know my feelings for him its gotten awkward. I can't find the courage to speak to him. I'm confused with him because a week ago he acted as if he returned the feelings, but now I feel as if he's avoiding me. While walking to another class he walked right beside me but then quickly sped up so he wasn't anymore. My friends always say he looks at me during classes but he just never talks to me, which is frustrating because I don't know what to do.

Some of my friends are good friends with A. One night a group of them had dinner because they all live in the same street, and my best friend went to ask A about me. She said he acted nervous and suddenly said he had to go home.

I would say maybe he is just nervous to talk to me, but he doesn't seem like that kind of person. A week ago he initiated the conversation on text but now we haven't texted since. And also, back when I had feelings for B, A still tried talking to me and asking me out. I just don't understand because now that he knows my feelings for him its going completely nowhere.

I have a sinking feeling that something is wrong. I don't think I did anything wrong, I'm a good person is what I like to think. I've never had a relationship because every guy has screwed me over, and I always get hurt. For some odd reason compared to the other guys, A is affecting me much more. Its not like he's said anything, he's the nicest guy in school and I can't imagine him being a like the others. I know I sound like a silly little girl but this is exactly how I feel.

Thanks for reading, I just need some advice on what to do and how to deal with everything because its screwing with my head. Thanks