OP, I hope it's clear that there's a fundamental difference between judging a situation and judging a person. You said yourself that having an affair is not good. And it's not. You don't need anyone to tell you that. I'm not saying you're a bad person because you've done this. Quite the opposite actually. I want to emphasize that you're too good for this. You now have 5 kids with 4 different men, so it's a trend. Why don't you think you're worthy of someone who will stick around and devote himself to you?
If I came on here and said my husband cheated on me and got another woman pregnant, I don't think the response would be "well, shit happens, can't judge it!" At least I hope it wouldn't be. Because it matters what you do. True, you can't help whom you love, but you CAN help what you do. And, since other people's lives are affected by what you do, all that matters is you do what you know is right. Not what you want, but what's right. I think we can all agree with that, right? It's what we all try to teach our children, right?
Again, this isn't about saying you're bad or evil. It's about saying you can do better. Because you can, and you have to, because yes, it matters what you do. It's not actually ok for this man to be cheating on his wife. And he's not a "devoted" father. A devoted father does not cheat on his wife. You can't separate the two. Anyone from a broken home can attest to that. You cannot be devoted and selfish at the same time.
You deserve better. There are men who will devote themselves to you, and you are worth that, as is your family. Best of luck to you and to your kids.