Anger Management?

I hope my therapist will be happy. I have finally reached the ANGER stage. It was triggered by the fact that my STBX made a huge fuss over something he normally wouldn't have cared less about. But since he's living with his mommy, and his girlfriend fell in love with him because he's "such a good dad," I guess he had to put on a show.
Long story short (probably already too late) the HS where my son attends had to evacuate because of a smoke detector that went off during a lab. My son is not in that class, but the entire HS had to traipse on over to the MS, where I teach, to wait out the fire marshal to say it was okay to go back. Now it's business as usual at the MS. I am teaching. I am not allowed to have my cell phone out, and when I am actively teaching I also can't check my private email. No big deal.
Seems the STBX shot me like 20 texts and emails- "Was our son all right? How could I be so cruel as to not get back immediately and withhold information?" 
Um. I wasn't withholding anything. I was working. And this stuff happens literally all the time. He has never once gotten upset before. Nor has he cared. As a matter of fact if I had called him in the middle of his "oh so important" work day, he'd have chewed me out for interrupting him. Literally, this might not have even made news at the supper table if my STBX had a "better" "more important" story to tell.
When I finally had a chance to text him back and tell him things were fine, he texted back, "Never mind. I called the school myself to see if my son was okay."
What an ass. Then he texted, "Don't worry. It was nothing wrong on your part." I texted the ass back that I never thought there was.
And there it was. The anger. And it was spilling out over everything he has done to us over the past several months. I was infuriated with EVERYTHING. His cheating, lying, uncaring attitude toward the kids, his selfishness over 25 years, and his big ugly GIGANTIC nose that I have always lied and told him looked manly, and which I would now like to punch him in. It would make him bleed and the big sissy pants would have to run right to the hospital in case his special chemistry was disturbed. (Can't tell you how many ambulance rides and emergency room visits and doctor's visits we've paid for when nothing was wrong.)
I have to admit, the anger was kind of invigorating. I don't want to keep the anger going any more than I want to wallow in sadness. Those are quicksand. I want to get healthy and move on. I'm not saying that I am in any way finished with this process, but if you're still hanging onto it years and years later, then you can't move on. You're bitter. And I am not going to give up the bitter for him. I am going to give up the bitter for me. And my kids. Except I am not there yet- Lol. So I will be bitter for a while longer. Probably until the divorce is final. Then I am going to give myself a set time frame to wallow. 2 weeks.
Two weeks. I am going to tell another long story short (too late). My mom and dad were happily married up until the day my dad died. They went through life's ups and downs, for better and worse, and in sickness and health. Both of them gave 100%. And they did everything together. They liked each other as well as loved each other. And when my dad died, I thought my mom would collapse. But she didn't. She concentrated on what had been good and that they'd had a long run. She was a nurse, so she'd seen plenty of instances when one loses a spouse. She gave herself two weeks. She let herself cry, be sad, eat very little, and she didn't attend mass (gasp!) And then her two weeks were up. She went back to church, called the ladies she bowled with and said she was back in, called up her card club and said she'd host the next round, went line dancing with her cousin who was also a widow and learned to love it, and started to attend events down at the senior center including the senior exercise workouts. She called the hospital and said she was ready to volunteer in the gift shop again. And my mom continued to live.
Now my STBX was nowhere near the man my father was. As my mother pointed out, as sad as she was and as much as she missed him, the Lord hadn't called her yet. That was several years ago. She is 80. And she still does all those things except bowl. Because she tore her rotator cuff. No other reason. She didn't date. (Well, she went out with one guy twice. She decided she would like the time alone instead.) And if my mom at 74 could learn to fill out her taxes, and take her car in for service, and all those other things I am letting scare me, then I damn sure can at 49. 
Don't get me wrong. She felt bad for much longer than two weeks. She probably truly grieved for four years. But she didn't let it stop her form living and moving on.
My STBX didn't die. He left me, and he left my kids. He doesn't really deserve any of my grief. I was a great wife. I was faithful and honest and trustworthy and I stood by him and held him up. I took my vows seriously, and I would have continued to do so for 25 more. And he flung me away like dog doo? What an ass. What a complete and utter ass. 
I know the divorce proceedings will get ugly and they'll make me feel weak again, and then I'll have to retrain my brain and give myself another pep talk. And the tears aren't gone for good. And the anger isn't here to stay but it will surely creep back in and out through this process. And I'm a long way from forgiveness. If I ever even get there. But I have decided that I am going to 95% okay. I'm going to leave that last little 5% for rainy days and Mondays and the occasional ghost memory that slips in uninvited. I'm going to call it a quirk in my character, and I am going to treat it with humor.
Damn! He lost a fine woman. Picked up a whore to replace me with. Like I said. What a dumb ass.