Exhausted in my marriage...

I work full time, have a two year old and am married. Lately marriage is on the back burner. Everything he does just irritates me. I get mad and I just start being a bitch, I know I’m doing it but I don’t do anything to stop. I feel like I’m just mad at him the whole time And going through the motions of life without truly enjoying it. I know that I’m doing it but I don’t know how to stop being annoyed towards him. We’ve gone to couples communication and therapy and I’m almost to the point why keep trying? Being a mom and working for what we have is easier then dealing with our relationship. ( two time history of him talking to other women during our marriage and an alcohol problem). I still love him and we still have good times together, but the annoyance and irritability towards him is stronger. How do I change that? Ugh! And we talk about wanting another child close in age to our daughter but I don’t know if it’s worth the added stress right now...sorry for the long post.