I know this is a late reply, but I was in a similar situation, I’d been with my ex husband for 11 years in total and we have a son who is 4 and a half. I didn’t hate him, but I didn’t feel anything for him, I loved him as a friend. We didn’t have intimacy though, he was never interested really and in the end I just became to nervous to approach it and also just simply was not attracted to him anymore. In October 2010 after he asked what was wrong one night, I just told him the truth. There was nothing bad with our relationship, we didn’t fight, but he didn’t really help with our son and be a part of our lives, I just said to him that I couldn’t spend the rest of my life in this way, I was too young to be living a celibate life and realised life is too short. I didn’t want to come to resent him one day, so wanted to end it. Naturally we were both upset, but after a couple of hours he agreed that it was right. I don’t believe he was with me for love, more companionship, he didn’t ask me to marry him, it was just agreed and he didn’t really want children. Anyway, I know my situation is possibly rare, as we were divorced 6 months after we split and it was so ridiculously straight forward people didn’t believe me, and he actually spends more time with DS than he did when we lived there.
I’m now with the true love of my life, and we are expecting our first baby next month. You are lucky as you have intimacy, and I would definitely try counselling, I suggested that years ago to my ex but he shot me down, really the alarm bells rang many years ago but I was too young and nervous to walk away.
Good luck and I hope things are ok, but don’t be afraid to walk away if you still feel the same. As a PP said, the children will pick up on it eventually if you are not happy. It is scary, but I am thankful that I found the courage to do what I did as the thought of staying unhappy until I died scared me more.