You would willingly leave your child for this guy? Is he really worth all that? This same man that doesn't want you to have any other men in you life, even your husband, although it's ok for him to have multiple women?
Personally I think you need to take some time to seriously decide what you really want in your life. Are your actions getting you to that place? That you left your husband and child to chase this other guy, then came back because YOU couldn't afford child support is ... (can't even think of the right words here). I feel sorry for your husband and your child.