I cant pick guys for shit🙄

So I lived with my boyfriend. We've known each other for years. Were together for a while. Well i have a daughter by another guy. (Who was abusive, but I got out). I thought that since you know we signed a year lease, he proposed to me, and we had practically set a date, that we were gonna do it. We talked about the future and everything. Then out of fucking no where he said "that you're lazy, you dont do anything all day while I go out and work 12 hours a day. And your kid wont fucking listen (mind you shes two), she throws tantrums and its bullshit. So you have 30 days to pack and get out." I was fucking shocked. Normally I would have said you cant do that because I'm on the lease too. But he could have left and i dont make enough on my own job to cover the bills and everything. Well there was no way I was just gonna stay there and get the cold shoulder and have my daughter hear us argue. So I left. And I know that in the long run itll be okay but damn I gave him everything I had. He had my whole heart. He still does, I cant just forget all the good memories. I mean he never showed any signs before the past month that he didnt like being a parent. So now she runs around saying dada or daddy and it breaks my freaking heart to hear that. How can he just flip like that? We were so happy, there was no warning signs except the past month. He would get snappy and I just want to know why he just changed so suddenly. I don't want bullshit answers. So thanks for listening to my rant about how I pick the worst guys apparantly.