Just...oh my God...I am SO done

Sunday evening, Alexis comes home from her friends house asking for a puppy. Her friend has yorkie-Pom mixes she's trying to find homes for and lex really wants one. I know, I know, I should have cleared it with Timmy first, but I told her yes. First of all, she is a great kid...16, but very responsible, respectful, helpful, and she never asks for anything. I think a puppy might help Alyssa's behavior also. I figure I will somehow broach the subject before Friday, my day off when I plan to pick up the dog. 
Monday I finally get my debit card in the mail, so I am able to pay back the young man at Walmart who helped me out last week, and it can grocery shop and pay Timmy back his $40 , that he loaned me last Friday for gas and toilet paper, his sodas, etc. oi give him the money, he looks at me and says, "ummm...don't you have a car payment to make also?" I just look at him, dumbfounded because really?! I'm not driving that car, haven't in over two weeks. I didn't buy this car, he did, without my consent or wishes. He didn't buy  this car for "us", but for him...to begin to establish his credit so he can buy a house. When he first brought it up, I told him we could look together, determine a payment we were both comfortable with, and both of us go on the loan. He threw a fit because this wasn't about me and he didn't want me on the loan. He makes noise about this being "my" car, but that only pertains if I am jumping through whatever hoops he sets up. I can only drive it when and where he says I can, I am to keep it full of gas and spotlessly clean, while he drives it, burns up my gas, and refuses to replace it. When I called him out on that, he threw another fit and told me he shouldn't have to put gas in it since it is HIS car. Not cool. I just now refuse to drive it. Anyway, I say no more about the payment, neither do I.
Tuesdays are my long days. I get to work at 8:30 AM and some nights I don't get to leave until nearly 9PM. At approximately 6:15, I get a frantic phone call from the girls. If they don't pick up the puppy that night, someone else is going to take it. I ask Alexis to call her friend and see if they can hold it until the next evening, as I work too late. I also figure at least this gives me one day to talk to Timmy about the dog. About 25 minutes after the first call, I get one from Jackie, Jordan's gf saying I don't have to worry about it, she went and picked up the dog. Great! Now I have to spring this on him after we already have it. What fun!
predictably, this conversation did not go well. He raged and yelled and insisted I had to take the dog back. Stared that it wasn't fair for the girls to get a dog before he got one, that 'we' aren't ready for that responsibility, blah blah blah. I decide to try another tactic and get Alexis to go talk to him. She leaves in tears minutes later because he interrogated her, and each time she tried to answer a question, he would cut her off and talk over her. She got so frustrated she cried and stormed away. In hindsight, I realize I shouldn't have sent a lamb to the slaughter, but I honestly believed since he truly seems to favor her he might soften. No luck. We reached a stalemate because I refused to give in, and he did likewise. 
After about an hour of this argument, he asks again about the car payment. his position is that, since we are married, I should help him make the payment. Finally, I look at him and tell him I've got a deal to make, I will pay HALF the payment and insurance when he starts paying HALF the rent, electric, cable, internet, grocery bill, house phone for girls, and half of all the kids need. He seriously starts yelling at me that this isn't fair to him. It isn't fair because if he pays half the bills this isn't a benefit to him, it only helps me to free up some of my money. Thing is, he's dead serious. He then launches into my irresponsibility with money leading to my problems and that he has a goal, to save money and build his credit so HE can buy a home. Paying half the bills is not in line with his vision. He is not going to take care of me so I can be better off while he suffers. Ugh.. From there I pretty much told him that I had finally realized this "story" about my irresponsibility with money was foolish and untrue. It is the debts he has accumulated in my mind, the money he has taken from me, and the fact that I am the one trying to make everything happen on less than he makes that hasncaused my financial issues, which I am now trying to repair. From there, he needs to know how much is in my savings account and what is in my checking, what my phone PIN number is, what I'm saving for, and oh yeah am I going to help him save money to buy a house? And what about the car payment. I am so selfish. Ugh again....
we are again at a stalemate. The next morning he calls while I am headed to work. Starts in on me about how he is just going to file for separation as we cannot agree on anything, he thinks this is for the best. He keeps asking what I think, finally I agree. He again loses it, screaming at me that I don't realize how serious this legal shit is, what is it that I want. Ugh again. I tell him I'm agreeing with him so there is really no need to argue. Thank God I got to work then so I could get off the phone. About 11:45 I get a text requesting I text him when I get a chance. I say what's up? He sends back how much he loves me and kids but he can't keep going on like this with me treating him like shit and nothing he does is good enough, but he wants to ensure he is making the right decision, as this legal shit is "no joke". I tell him I love him too but am unwilling and unable to continue on with things like this. He sends back that he also met with a counselor who told him that once we sign this we seal the deal. So really, he expected me to believe that within two hours, with no appointment, he's met with both an attorney and a counselor!? I just didn't respond. 
I got off work at 5 last night and texted him as I always do to let him know I'm leaving work, picking up the girls, and going to my nephews football game. We do, and we stop at walmart afterwards. I walk out to the car ahead of everyone else. The girls stay inside with my sister. He is there and comes to the car. I am bombarded with questions, why didn't he know I was coming to walmart, why didn't I ask if he wanted something(mind you, he was also shopping there, came outbwith a car cover, and yet he didn't ask me if I needed anything). Then he needed again to see my phone to verify who I've talked to all day, and I should walk in to buy a new phone, battery and tires for my car, as he bought those and he's taking them (forget the fact that they were bday, Christmas, anniversary gifts). I tell him to please stop, he is embarrassing himself and me. People were in their cars staring at this scene unfolding and he was being clearly irrational. He storms off finally. Apparently someone had called police because here comes four police cars flying in and driving around the parking lot. Anyway, my sister comes out, they caught the end of that rant, she and I are talking. About 15 minutes after he left, we go to leave. Phone tongs, it's him to ask if I can run in and buy him deodorant....as if nothing happened! We get home, I go to put something away, he's lying in bed, grabs my arm and tugs me down on the bed, kissing me (something he never does), and says he can't understand why I'm acting like this?!?!?!?!?!?!?
this morning, more of the same....we need to get lawyers, file separation, I need to type up the agreement and have it notarized, he's also trying to convince me that we can be separated yet still live in the same house (something I know for a fact is not the case in md). From that it was back to how I'm messing up his goal if he moves out now. If only I would just........fill in the blanks, we wouldn't be having problems. Ugh one more time. I'm exhausted now so I'll write more later