i totally agree with JD. hubby needs professional help. the odds are not in his favor if he doesn't. that in turn impacts you. i'd lay down the gauntlet on this situation. if he resists from the start you have your suspicions confirmed. if he willingly goes he's got a chance of recovery. i know ppl who have this addiction. they revert back to their old ways, some even after they got help.
as for your relationship souring well why wouldn't it after this betrayal of trust?? if you want to try to make a go of it with him i'd suggest you all going out to dinner once a week, not casual, and put some romance in your lives. he's got to be onboard with this. if not-kaput. a good heart to heart with him to see where he stands if in order. i'd tell him exactly how you feel. he caused the problem so he needs to try to put things right.
and of course you are a beautiful lady. your life has been sorely bruised. get on with it even if he doesn't want to participate. join something you're interested in, lunch with friends, anything to spark your spirit! don't let his actions damper it. he should feel less than, not you.