If your mom is aware of how you feel is it possible to leave your husband and go and live with her for a while while you get your feet on the ground with a job? If you want out of your marriage get out of your marriage. What I see happening though if you stay where you are is that you won't be able to financially leave until you find someone else to support you. At one point you loved your husband, you have raised kids with him and you have had a life together. To leave him for someone else, someone "better", just sucks. It's a cowardly way out.
I know that I sound harsh but I have been on the outside of this looking in with a couple of close friends last year. The fallout sucks for everyone around you when you split up because of cheating. Since there isn't anyone else in the picture right now it's time to work on a doable plan to get out of the marriage for the sake of ending the marriage, not because there's something shiny and new on the horizon. Once the marriage is over (and be firm with him that it is and you're not coming back) then you can start pursuing other relationships and other forms of relationships.
Everything will be ok in the end. If it's not ok it's not the end.