Life is a spectrum. I think all men, even us gay men, view women and can still say who is attractive. I've always surrounded myself with women. They are close friends, confidants and can understand me easily. However when it comes to sex and who I desire emotionally for love that has always been a man.
You face a hard decision. It would be one thing if it was just you and your wife. You are lucky. Yours is giving you space to figure yourself out. The major thing that anyone who even glances at this is going to focus on is your child. Your wife and you brought this young life into the world. Your responsibility will always to be to the child. If living in the same house hold will cause your child more heartache then staying together would that is something you need to decide.
I have seen gay parents who were married make this work and their children loved them both. They have accepted their straight parent and their gay parent as well as the mates they have chosen. I have also seen people try to stay together for the sake of the child. Eventually, cheating occurs, fights, and the child is the one harmed emotionally.
No one can tell if you are bi or gay other than you. You might decide you need counseling of some sort. You might decide you and your wife can yet make a go of it. Whatever you decide be honest with yourself and her, but always keep the future of your child in mind. I wish you the best whatever you decide.