What to do

I have been with my boyfriend for three years now and we have had many good times and many bad times. When we first got together he cheated on me. I forgave him and I got pregnant a year later. Having my daughter is a blessing. Two months ago I caught him texting another girl. It destroyed me once again. I have tried to forgive him and move past it but it seems like between babysitting my daughter and now feeling like I have to babysit him i no longer can focus. I am always worried about being cheated on and getting into fights with him over it is getting really frusterating. He won't go to therapy and he lately just has a short fuse with me. Does anyone have any advice on this