As far as the practical side, I'm with @drscorpio , I think. Also, don't forget that even if they are only having oral sex with other men, there are plenty of STDs they can pick up that way (HSV, chlamydia, gonorrhea, and syphilis, to name a few).
As far as the relationship side, I know from very painful experience that it's possible to love someone (or more than one person) unconditionally and have them love you back, and yet for whatever reason have them treat you badly to the point where you cannot live with it. Only you can make that decision, but if the way that they are treating you badly is damaging to you (and the line "I also don't want to feel used having one of my guys saying "I love you" and calling someone else "daddy" in secret. That makes me feel worthless." is extremely telling, here), you need to take it very seriously. That kind of damage can be very hard to get over, and can slop over into all kinds of other areas in life; also, it is insidious because it can happen gradually in a non-obvious way. I'm five years out, and still having trouble putting my life back together. You may also need some outside help to get a more objective view of the situation - I had to talk to a therapist.