Hmmm, i think you need to sit down with your wife and have a good, serious chat with her, alone.
Tell her your issues and what you want out of your relationship.
If she doesnt want to listen and says its all in your head, then you should make preperations to leave her. Dont worry about the relationship with your baby, you can still have one. It will be hard, but managable.
Hopefully though, she will listen to you and understand what your troubles are and try to make you like her like you once did. Dont forget its a 2 way thing and she may feel the same about you.
I think its common for couples to 'go off' each other, but i think if you communicate well and try to remember the good things which once attracted her to you then you will be fine. Your only pessimistic because you feel down.
Personally i think its all down to lack of sex that you feel like this...