serious advice please I'm losing it...

Anna M. • FTM, four miscarriages and the sweetest baby boy born in May 17
It seems I am begging to lose my patience ... we have been together for a couple years now, living together, my partner has an excellent job (extremely busy) and I run my own business. I am pregnant with our first baby (he has 3 from previous relationship and two of them are in college). I get upset every time he goes to see the kids, because he goes to his ex wife's house, (she forbids them to come to our place and my partner accepts it) he also pays tons of money for the house because she doesn't work. Today he said he will get more bills to pay for her because she doesn't know how to pay her bills. He used to do that and she continues to use him even though they have been living apart for years! We got into a fight, again, he says if he doesn't pay for her she won't (she apparently doesn't know how to make a wire) and it's for his kid. She is perfectly capable of all of it, just refuses to work because she can get more from him if she doesn't (recently pushed him down the stairs demanding more money) she is hysterical, physically and verbally abusive. I'm losing patience when i see he doesn't have the time to help out at home with basic stuff but has to find time to figure out all her basic house chores! Last weekend his son made him buy her a new tv (" for the youngest kid, not for her" right!) but she will not contribute to anything! She goes to a hairdresser a few times a month, has recently got herself new tits and new face but cannot organize herself to pay basic house bills? She has the money, from my partner, but needs it for other things and won't take responsibility for her life. I'm fed up with my partner being at her every beck and call just because he is afraid she will not let him see the youngest son. (Case soon in court, maybe) I'm pregnant and need him to focus on our house! Am I being selfish? He makes me feel like I'm being completely unreasonable and put up a fight for nothing! I just want him to finally cut the cord with her, she is not even a kind person, Loves to threat and lie, used to hit him and still sends abusive messages regularly). Then my partner lies about things not to make me upset and I just explode every time I discover the lies. I am going crazy! Is it me? Jealousy? Am I so completely insane? Do I create the unnecessary arguments? Sorry for the enormous rant. We were planning to go away this weekend but as always there was a last minute change he went to her house to see the kids who came home from college.so I'm home alone again.