Two thoughts come to my mind:

1. It's not easy, but we need to forget about WHY for now. Totally forget about it and throw it off to the side. It would be nice and give closure to find a "why", but we easily drive ourselves crazy looking for it and we don't even need it to take action and change our attitudes and circumstances. Analogy: if your computer crashes or freezes, you could search for the reason, but if you just reboot it you can get back to work--if it dies, just get a new computer. It's nice to know what happened, but sometimes you don't have time for it, and you need to keep on the task that was at hand more. In this case, the task is you and your health and situation, and that is worth a lot more effort than understanding why people are being jerks or your car is breaking down. Does that make sense? (Hope it doesn't sound too terse.)

2. Failures and mistakes are good and have to be accepted because those can teach us more than anything else. Breaks and bailouts don't grow us at all. It's really uncomfortable especially when we're depressed, but I like the way Dexter Yager says it: "Failures are just stumbling forwards to the next success." As long as you keep going, you make mistakes along the way but you're not failing because you are succeeding at keeping going and learning what you need to do.

Okay a third one came to mind:

3. It's OK to be the "bad guy!" Actually, you have to learn to accept being SEEN as the bad guy (even though you probably aren't the bad guy.) When you draw a line in the sand and say 'I won't accept this,' you become an easy target for complaining and blaming and crap like that. But you also gain self-respect and you reject that bad treatment, even though you will catch heat from that person. Let them be mad or whatever--that reaction is up to them, not you. But you're taking care of yourself will pay off in the end.