Hi Starz,
I'm sorry you're going through this. I've been through similar things too...and I have also dealt with a lot of negative self thought and suicidal thoughts. Like Potatofree, I think you should find a counselor or therapist to talk to. Even if you don't feel like they'll help, it would probably make you feel better just to have them to talk to. A counselor could also help you with the negative self-thought by giving you feedback to help you see things more clearly. It may take some time to change your patterns of self thought, so be patient with yourself. (I'm still working on this myself. )

This man leaving does not change who you are. You are still the same beautiful, intelligent, strong person. If he did this, then he's not the right one for you. You deserve better than that, so don't let him make you feel negatively about yourself. It is his issue, not yours.