Please don't make any hasty decisions on this. Firstly, someone else mentioned that coming off ADs can affect you badly and you don't want to be changing your whole life if not seeing the whole picture clearly at the moment.
From my own experience though, you should think very long and hard before splitting up with someone who is a good father. I know it can be easier as a single mother than coping with a difficult partner, but it doesn't sound like your DH is actually causing problems so instead of shutting yourself off from the relationship emotionally, talk to him about how you can find a way through this - so you can have some time together, so you can have time for hobbies, rest, whatever.
Both DH and I are on second marriages with children by other people and it is a minefield. Splitting up is not just about coping with life as a single mother. It's about finding a way to make your children's lives work in two homes (what if one of you moved away and there were distance issues to deal with? what if you argued over access arrangements? different house rules?), it's about working on blended families in the future (you don't want another man in your life, but might he want to have a new relationship?), it's about sharing your time with your children (do you really want to lose half your weekends and holidays with your children, just because you were bored?)
I don't think I'd have done things differently if I'd thought about the true implications of divorce with children, but it's been bloody hard even knowing that I was getting out of a bad relationship. If there was nothing really wrong with my ex-H, I would find it very hard to forgive myself now for ending things without trying to find a solution to the problems.
Think about what your life would REALLY be like without your DH, but also think about what your children's lives would be like. Obviously nobody should stay in an unworkable relationship for the sake of the children alone, but they should definitely be a factor in working harder at it and, I'd have thought, worth some degree of boredom.