Don't be a Negative Nelly. Start thinking positive. Psych your mind into thinking good thoughts. Whenever you think horribly about something, immediately replace it with a happy thought. Mine happens to be the beach...
That doesn't make all the problems go away but it sure is a heck of a lot better than being depressed.
Do not give her a time limit on "when things should be fixed by." I think this is a huge no-no. Tell her that you've decided to go to counseling to work on your anger issues. Tell her you are willing to try MC with her and are willing to fight for the M. Then see what she says.
You sound a lot like my H. As for the anger, has it always been an issue or just got worse now? What triggers it? Just from my experience, each time you said No to her when she'd invite you out, she experienced it as a sort of rejection. You can read up on my sitch so you can see her POV.
The fact that you recognize you have an anger/verbal abuse problem is step #1 so that is great news.
Also, her spending holidays with you is a plus side and I believe works in your favor.