Moved in with baby's moma B4 birth, child is 6 months. Have another child 8 years that's lives with me 50/50. Baby's moma has a teenage son full-time.

Me and baby momma function as a couple and even bought each other rings to look like a married couple. Things go as smooth as they can for a blended family.

Here's the problem, ever month like clock work, durn her period she breaks up with me. One to two day fight. Luckily it's not physical, knock on wood. I tried different strategies. I don't think she's cluster b so we can rule that out. But I don't think I can do this for years. Help!