I read your post and wanted to let you know, I have 2 children who are normal, well rounded, teenage boys. Both live normal, active, teenage lives and the fact that I live a poly lifestyle has not effected them adversely in any way, as a matter of fact they have grown to love one or two of my former partners. When my husband and I meet someone we want to be with we let that woman know up front that our kids are important to us and then we see how she is with the children. Now, here is the hard part, if for some reason the children don't take to the woman or her to them you gotta be strong enough to let the other person go...their needs come first.
Like you I too was raised that homosexuality was bad (thank you mom and dad for moving me to the Bible Belt) and it took my finding a very understanding man who helped me understand that what I was feeling was not bad but just a part of who I was. At first I was afraid that my needing to have the companionship of another woman would hurt him in some way but he helped me to see that it in no way hurt him and he has even helped me find a partner and we were doubly blessed when the 2 of them were able to form a relationship too.
It will all work out and if someone doesn't understand you or puts you or your lifestlye down remember that most people are afraid of that which they don't fully understand.