cheated on BF with my husband/ ex husband

So really quick run down I was with my husband for 7 years , 3 years ago we split (my choice) it is still very hard because we have two children together . We have filed for divorce but still have not been legally divorced yet . I'm so lost because lately my heart has been so heavy. I have a Bf and I love him and he's so good to me . Something my husband was not . But my BF is on and off of jobs and like any relationship we have our problems. Just the other night I was in tears and just so emotional . My Bf ask's what's wrong and I tell him ... my heart is just so heavy right now for my kids I know they want their parents together. Well today I mest up I went to my ex husband / husband to pick up my daughters uniform for her game and while I was inside he grabbed me and although we didn't have sex we did other things . At the time everything else was blocked out. After I left I know I mest up . Cheating is wrong no matter what . I honestly don't want to tell my Bf I know he will leave me . I'm writing this post for advice please be honest but please don't be rude . I'm an adult and know that I'm wrong for what I did.