clw, if you choose to work on your marriage that is absolutely your right to do so and I wish you nothing but the best.
I do hope you know that the fact that you hadn't had sex with each other for 2 months had nothing to do with this. He could have taken things into hand..in the pun way, and better yet, in others, by talking with you, helping you with the housekeeping so you would be less tired, arranging times of rest and romance etc, finding a babysitter...many, many things.
(((((((((((((hugs)))))))))))))))))))
Having a young one is very exhausting for a mother and a working mother even moreso.