Just been to Marriage Builders and been told to just forget her as she's not worth it if she can cheat on me after only 6 months of marriage.
That's your decision and yours alone. No-one else can decide that for you.
You have to remember your W is in lust, not love.....even if it turns to love later. However, judging by OM's past history, it won't last.
If you want another chance I think you are going to have to wait it out, and to be honest I would go dark on her.
Are you sure that the stuff with OM wasn't going on longer than you have stated - something just seems a bit fishy about the speed with which he moved in on your W.
Personally, I wouldn't date - you are vulnerable. However, I would socialise and make sure you have little time to brood. Also, take the 'high road' approach and act better than W and OM so there is no come back on you.
