Husband drama

So about 6 months ago I caught my husband sexting another woman. I left him for two days and went back. I had just had my baby girl and didn't want to be alone and I still loved him. Fast forward to now. We cannot stop arguing, and when it's bad, it's really bad. But when it's good, it's perfect. I flew down to help my mom for when she has her surgery (she has cancer) and ever since I got here he has been so mean and accusing me of cheating on him every single day. I went out to a party with my brother, and ran into an ex boyfriend of mine. We talked, but nothing happened. My husband and I have been fighting non stop and he says things such as " I would rather put a bullet in my head that spend one more second with you." Finally I broke down and got the divorce papers. They are just sitting there filled out but I can't bring myself to file them. I want to, but he keeps talking about how much he loves, misses and can't live without me. It's making me feel terrible!!! I love him, but I don't trust him and I can't get over what he did.