Relationship advice

So me and my bf have been on and off for 2 1/2 years I got pregnant with my son at 1 1/2 years. We argue ALOT and ever since I hit the 2nd trimester it has increased a ton! Ever since i had him I'm no long attracted to him (personality wise) I'm a different person and he's just not what I want anymore. But I can't bring myself to break up with him. I have told him how I feel multiple times and it end up with arguing. I have had thoughts of cheating and doing reckless shit just so I can get away from him or to make him break up with me. He also has this thing where he lies.. for example he'll huff if I lecture him and then when I ask him why he did that he'll make an excuse like I was just breathing 😑but he buys me stuff to try to make me feel better I appreciate it but I'm not materialistic and I don't want him to flip out and think I'm using him for money but I want the best for my son he is ALWAYS my #1 priority and I've had absent parents for as long as I can remember. What do I do.