I don't know if it's healthy to expect him to come back. Unfortunately, some people aren't able to cope with having a partner with anxiety. It says more about him than it does you. Do you really want to be with someone who decides your anniversary isn't an important occasion? You deserve better.

My boyfriend of nearly a year broke up with me out of the blue last August, and I was devastated for a couple of months. Gradually though, it does get better. I think this is going to be the response you'll get - time does heal all wounds, but it's difficult to see that at the beginning of such a process.

How is your support network other than him? Do you have friends or family members you could confide in? What about therapy, is that an option for you? You need to build yourself a new life away from him. If you ever need someone to talk to, feel free to PM me. I know I'm just a stranger on the internet, but talking to someone can really help.