I feel your pain! I wish I could tell you to move on because that seems like the best thing when reading your post. Well moving on is easier said then done.
I wish you the best in the days to come. Try to put your child and yourself first in the things you do and decided.
My husband and I have been together for 11 years and married for 6 years. we just decided to separate to work out our differences and work on ourselves for a while. The marriage has been down the tubes for the last 3 years while he has been in college. I missed the signs of my husband cheating on me with a girl in his class and he stopped wearing his ring about a month he said it was due to his finger swelling up. Now here i am feeling soooo bad and asking myself why? I know I wasnt the best wife but I always took care of him. I cant give you any advice but I can say I am right there with you in your pain. Dont ever feel like your alone in this.