Let me just hit a few points here:
1. Suicide is the most irresponsible choice. Just know that doing this only effectively hurts the ones that love you. It doesnt free you, it doesnt make them happier, and in this case it would take the life of a potentially beautiful child with limitless possibilities.
2. If your lover's family is overjoyed, why not let him have full custody and try to work something out with your husband. Or if it's over with your husband, are you so against keeping the baby and staying with your lover? Does your lover know you're married? It is a big shit sandwich so no matter which end you bit it from it will suck, but the longer you delay the inevitable the harder it will be.
3. Being your lover's child, you had better be certain he is included in whatever decision you make. That child is as much his as yours, and even if you want nothing to do with either him or the child, there is no sense in taking the childs life and ruining your lovers life in doing so. Just by the fact you haven't gone through with it yet, I know you're not that selfish.
4. Follow your heart, but dont think you have to do it alone. Talk to both your husband and your lover, and let your heart guide you. You cant make the decision for you alone, now it's a decision for you, your baby, and the baby's father.
Anything I can help with, email me. chicomarxeinstein@gmail.com
I dont know that I can offer much more than someone to listen/talk to, but given your situation I am more than willing to do that.