Why am i feeling like this over my bd vs my bf

My current boyfriend and i had sex for the first time yesterday and i almost called him my kids father name multiple times while we were doing it, it’s like i couldn’t stop thinking about him all of a sudden.

I been with my kids father for almost 4 years and i decided to leave him because i feel like our relationship couldn’t be fixed so my current boyfriend and i waited 3 months to have sex and it was horrible.

It wasn’t good at all, it’s like he was trying to hard and going rough for no reason and i didn’t like that and i think he noticed it.. he even asked me if i came and i told him no and he seemed shocked and i don’t know why, as soon as we got done, i got dressed and i made an excuse to leave.

I told my best friend i think it’s because i been with my kids father for awhile that maybe I’m not completely over him ? I haven’t thought about him since we broke up or cared enough to talk to him so why am i feeling like this now ?

I almost broke up with my boyfriend because after yesterday it’s like all my feeling for him just disappeared.