Jay, when people really piss me off, and make me feel like crap, this is what I have learned to do. I figured this out when my fiance left me about 12 years ago.

Get up, brush teeth, take shower, dress in clean clothes anyway. It takes a monumental effort. Sometimes I have had to pretend I was happy Amazon instead of severely depressed Amazon. I kept on living. That way, I didn't let the people who hurt me win. I won, because I kept on living.

It doesn't always work so well. But it helps for me. I also recommend therapy, because it really does help you through traumas.