How do you stop being angry all of the time?

Do you have some anger from when you were a kid? If you do, can you talk about it with your therapist?

How do you stop being sad all of the time?

Have you talked about your sadness with your therapist?

How can I get him to stop pushing all of my buttons&yelling at me-both of which are triggers for me.

It sounds like you have tried to get him to stop and you don't want to leave. Whenever someone has pushed my buttons I started working on those buttons so that they could heal and then no one could ever push them again. When he yells do you yell back?

I've told him what's wrong w/his behavior but he won't acccept any responsibility. He just screamed at me "You are always accusing me of victimizing you!"

It is hard to control someone else's behavior. One way to get someone to listen is to say "When you do _____, I feel _____". When you say it this way there is no blaming or judging the other person so they don't get defensive right away and there is a better chance that they will listen. Stay calm also and don't start yelling. People listen better this way.

One of MY problems is I give all of my power away- I just go along with whatever he says because otherwise we'll end up in another argument where it's all my fault

You can work your way out of this one step by step but you have to focus on what is going on with you and you have to figure out yourself and what you need to do (problem solving). None of this has a quick fix. Getting better requires time and work. I can help you but you have to do the work.

lays all blame for any problem I'm having on me. How is everything always my fault?

If you are the one with the problem it is yours. This goes back to the fact that you cannot control anyone else's behavior. If you take responsibility for youself it will empower you.

&the fact that I still care about what my bf thinks of me&whether he loves me.

Are you a pleaser, will do whatever you need to for acceptance and love?