My cheat husband has finally signed separation paper guarantee me support & custody, why do I not feel better?

Happily married for 26 years! We hit a rough spot with 4 years of one family illness after another. He became discouraged and the right temptress moved in. He left 4 mnths ago and has been with her ever since. He has had little or no contact with me and our age 16 daughter. I thought that pushing for this agreement to ensure that I could take care of our daughter would help more than this!! I focussed on doing what I felt I had to do!! It was a rough fight, but he did not want to go to court any more than I did because of negative publicity. My heart has been broken, I have cried a million tears - as has my daughter. I do not want to take everything from him as everyone around me is advising, I want to know that he is ok; but I do not want the woman he cheated with to have the profits from 26 years of he and I working together to build a business from scratch. I feel that all that should go to our children. I have most of that in writing notarized! I still feel unhinged/lost. Now what?