Its a difficult situation to be in. I myself have been on your husbands side and have been through rehab here myself. Whilst in rehab they say about letting go of the past and to move forward as a fresh start/clean slate and not think about what you have lost. For me this wasnt just about money, but making relationships with friends and family better moving forward.
It sounds like it is working for him so far, and sounds like he is doing his best to make amends. It may be though that you are never able to fully trust him again. How would that make you feel?
The only real thing you can do yourself is to limit the damage if it does happen again. keep yourself a bit of money put away, so if it did happen it would limit the financial aspect of it and you would still be ok. Ive known far too many people that have blown every single penny they have had, and you have the power yourself to majorly limit that kind of damage.
maybe build up the trust over time with money, start small amounts (I dont know your financial situation or whether or not you even trust him with money to go shopping or suchlike, but you have to start somewhere?)
However you do it its not easy, and time is the greatest healer.
wish you all the best