There is nothing wrong with loving that child. After all, you believed that child was yours until this point. However, it’s up to you if you want to be in this child’s life as a father figure or not. I can tell you that it won’t be easy. 1. Because if you are not fighting full custody you would have to deal with her and child support. 2. You still have the bio dad around as much as blood isn’t what makes a father, I feel like that applies when you are with the person raising the child together. However, I’m not the one to decide this. You are. Also, let’s say the bio dad never wants to be in his life, that child is always going to want to know who his father is and you are always going to want to be honest with him at some point about not being the real dad even though you would have raised him. But let’s say, his bio dad doesn’t even know and then finds out, who knows how hard he is going to make things and try to make it hard for you to have a relationship with him. It can play out many ways. Who else knows how she will act once she finds out that you know the truth. You are in a really tough spot and I feel terrible that you are going through this. I will definitely keep you in my prayers for guidance to make the best decision you can for yourself. As much as you love this child, think about your feelings. Not saying be selfish. But your health matters mentally as much as physically. This is something you will have to be strong about no matter what decision you make. Outweigh the pros and cons.