I made a mistake 😢 (really long)

I'm sorry but I have to get this out there.. I really don't wanna be judged I'm sure somebody will. I'm almost 22 and just my 3rd baby. Well I've been in this difficult relationship for the past 5 years. I already had one kid before I met my boyfriend and we had another one together after a short time of being together. And after 4 years of a hard relationship we broke up. He left and I was told he was happy with another girl so my dumb idea was to try and move on with somebody else. Me and this guy slept together once(I know it only takes one time) and I told him to wear a condom. After a couple weeks me and my boyfriend tried getting back together and at that point he was trying to get me pregnant. Well I did end up pregnant. After a couple months we got into a fight and he told me the guy I slept with said the condom broke or something. I didn't believe him because the guy didn't tell me personally so I figured he was being mean. Well now my baby is a couple of weeks and he doesn't look like my boyfriend. Now I have 3 kids with 3 different guys and I feel like crap. I'm definitely crying a lot from this. I don't know what to do because I don't wanna leave my boyfriend but everybody wants me to because he's not the best person. And I know the right thing to do is tell the other guy about the baby but I'm so hurt and I know I'll never have the happy family I always wanted.

Sorry for how long that was I just need to get it out.