Final exam sabotauge

Today was my final exam for the fundamental nursing course before hospital rotation next week. D showed up with his Russian buddy after he had texted earlier that he would watch the boys and knew about my exam and wished my luck. Later that night I was reallly running behind on everything after making boys dinner and baths and asked if he could put them to bed as the little one sometimes stays awake up to an hour after I turn the light off. He said he'd put Davor Skyler to bed, but didn't want to put the baby to bed as he might fall asleep and it'd interfere with his plans to play video games. He shows up at 10:45 after the lights are out, stories are read, and I'm really stressed that I need them asleep so I can study. Of course he comes up stairs, opens the door, and if they were about to nod out they abruptly awoke and got all excited to see daddy.
I was mad that he could be so insensitive. He only cared about his plans for the evening, not whether I could have some quiet time to focus. I shut the door to the stairs, didn't slam it, but he claims I did. We started arguing and it turned into this all out agenda to rip me down. I thought I really had a handle on things and that it was beginning to feel that life with him would be one committed to misery. He kept repeating that I was fat and ugly, and that I'm an alcoholic and lazy. He then threatened to not watch the kids again when I rely on him. I told him I finally have things in place with the state, and will find reliable daycare that I won't stress about some mood swing impacting whether I can make it to school. I added that once I commit the boys to a daycare they will be there every week, and not just when he feels like screwing me over. I said that would nearly eliminate the time he gets to spend with them as those two days are really the only days he's not working.
He got violently tempered, I was screaming, our 5 year old was standing between us with his arms straight out with his hands in a "stop" position. He lunged at me, chased me around the dining room table, and threatened to kill me. He assures me that it's an empty threat, but now with his cage fight training I fear that he believes threat is the best way to get what he wants. He kept calling me a whore, though he's the one sleeping around. He added that "I'd be surprised how young some of the women are" that he's been with.
I had to go to a Work First orientation after my exam. I understood it would require all of today, but then someone mentioned that as I have the week off from school I have to commit 40 hours there this week. I had the whole week planned. I wanted to paint the boys room, clean/organize mine. Take the boys to a pumpkin farm and get pics. My weight is magically creeping up, so I wanted to work out daily and get it in check. As I've had days where I wanted to jump off a building lately, and the stress of these intensive classes, I had been counting down the days to this week off to straighten out my head and environment to prepare for the hospital training and the ridiculously early mornings. To think I'm going to sit in this classroom filling out job applications while all my plans burn to the ground makes me livid.
I came home briefly at lunch, got into it again with the Ex, and as I was cooking he pulled his fist back and threw a punch at my face, stopping just short of contact. I went to the police station to see what rights I have when he refuses to leave my house while calling me all these nasty things. It turns out that his behavior is still assault, though he doesn't hit but makes the threat, and if I file a report he will not be allowed to come on this property at all. On one hand he isn't the same person from years ago, and I worry how badly he might really snap. The other side is that he would only get that much more psycho and threatening if I took it that far. He texted, "sorry", and gave me a hug later like that makes up for all these profoundly hurtful things he's done. He is an abuser and an addict. He's grasping for straws and using what's left in his arsenal to hurt and debase me.
Meanwhile I bought a car and was told it needed a transfer case. I bought the transfer case, take it to the mechanic, and it's not what was wrong. It needed a differential. The guy who sold me the part swapped it out, and I told him exactly the part that was needed. He asked that I call Sunday morning to arrange an exchange, but didn't answer any calls. I texted that I hope he's a man of his word, which set him off. He basically told me I was lying about calling, and was rude, and forget about him helping me. He finally realized there was a voice mail from me and apologized, I got the part, my mechanic put it on. I finally pick my car up today, the first SUV I've ever owned, and was so excited to finally drive it. Turns out it was not the correct type of differential. The car immediately started thudding and now I'm left wondering if this guy will take it back, what I'm going to have to pay the mechanic to put another one on, and where the money will come from. My week has gone to utter shit. I want to curl up in a ball and stay in bed all day. I thought I'd have that kind of option to finally have a reprieve from school demands and spend a little time reflecting, but now these Work First people are screwing me out of that. It sucks.