C.O.
MM:
You're in a pickle. Most open marriages are for "fun" not for developing a future spouse...it's for "ef" buddies - getting what you can't or don't get in the marital bed and still keeping your marriage going strong.
Most couples who have open marriages are EXTREMELY close and have a STRONG, solid marriage. Yours doesn't sound like it was strong and solid. So the playing on the side showed all the cracks in the foundation and even put HUGE GLARING lights on them.
Step out of your box. Pretend you are your best friend and you are trying to help her - what would you say to her?
If it were me? I would stay and work on my marriage. The grass is NOT greener. You've seen this guy in his good times...when you leave your husband for him? Your "new man" will lose his glow and charm. Right now? You are in the "fantasy" part of the relationship - basking in the glow from all the good things he does...however...you'll get in the rut...you'll get the bad days....it will NOT be all wine and roses...
I would tell my husband that it's obvious our marriage is NOT strong enough for an open marriage and that we need counseling to make our marriage what WE WANT IT TO BE - then you won't feel the need to go elsewhere.
The grass is not greener.
If your husband is verbally abusing you and the children? DEMAND counseling, anger management, etc. If he's willing to work on those and actually does it? You've got a keeper. If he tells you it's not his fault and if you wouldn't mess up, he wouldn't have to get mad? Drop him like a hot potato. Get counseling for yourself and DO NOT get into ANY relationship for ONE YEAR - and that's WITH counseling.
You need to end one chapter in your book instead of skipping to the next without finishing it.
Good luck!