Pregnant and separated

We have tried for three years to get pregnant but I caught him cheating so many times with ugly women who are homeless on drugs etc. then he blames me. He's a compulsive liar who won't stop drinking. I'm deff done with him cuz I deserve better but why do I feel so terrible!? I just found out I'm pregnant due a day after his bday on our other daughters bday. He's never happy. I do everything. I work cook clean take care of him and the kids go food shopping pay the bills etc while he plays video games. A loser I know but he wasn't like that before. Idk what to do but leave him. Am I making the right choice? We've been married for three years together for 11 yrs since we were teenagers.