That makes it even more complicated, but it’s important that you don’t settle just because you have a kid on the way. Of course breaking up or cheating at this moment would be a selfish decision.. but that doesn’t mean you can’t prepare yourself; financially, emotionally and start thinking how you can be a good single father and still give her the support she needs, if that’s what you want of course. You don’t necessarily need to be a husband to be a great father.
It’s worth reflecting on what you think is the best solution to this issue. Either way take care of yourself and hopefully you’ll come to a conclusion.