Why are boys so confusing?

I need help and advice.

I have been talking to this boy for about 3 months now. We met though friends at a party. He broke up with his ex about the same time I did, and after the first or 2nd month, I stayed at his house and things were amazing! He usually texts me good morning and good night but lately he hasn't been and he has been leaving me on read? That's not the biggest problem but his ex tried to get back with him and that kinda of annoyed me because he always used to talk about her, and I never talk about my ex to him. Why is he sending mixed signals? We have never talked about making things serious but we know we like each other, I just didn't want to rush into anything too early because I'm on my last year at school and I want to focus on that instead of boys. What should I do? I don't want to sound too desperate too early but then again I feel like I have a right to say something because we have gone pretty far. Pls help???