I think it will take a while to "get over" this - it's a loss that is causing you to grieve and it just goes at its own pace.  Of course, you're feeling hurt right now, I think anyone would under the circumstances.  Depressed people so often shut out the people who are closest to them, almost as if they're afraid they're contagious and don't want you to be hurt.  Of course, that's depressive thinking and not rational, but it's very real to them.  When he told you he would never break up with you, I'm sure he meant it at the time.  We all know, however, that we can't predict the future and what things might happen that would make it impossible to keep that promise.  Married people divorce all the time and I'm sure they had good intentions.  Maybe it would be helpful for you to get some help for yourself in coping with this.  I wish there was a magic pill or something that could help.  Just know that you aren't alone.