Stay strong Candy- I need to be brief as am expecting visitors but my to cut a long story short DP is a 'recovering' compulsive gambler.
In my situation what turned DP around was hitting rock bottom with his finances which resulted in me packing his bags and refusing to continue our relationship until he got help.
Its kinda difficult though because IMO the gambler will only seek help when they truly want to- you can't make them, but you can show them that you really really mean what you say.
If you truly feel that you cannot continue being married to him unless he changes his behaviour (which sounds sensible to me) you have to stick to your word- otherwise he will never believe you in the future.
I am really sorry to say this but gamblers are fantastic liars- so don't just take his word for it if he promises to stop. I would suggest: he goes to GA, he closes all accounts with bookies and self excludes himself from all local ones, agrees that you can ask to see his bank account whenever you choose. He may feel this is some sort of 'intrusion' but my DP agreed to this on the basis that he had thrown away my trust and needed to take these steps to build it up again.
Some couples agree to the non-gambling partner taking full control of the fiannces and giving the gambler 'pocket money' but I was not keen on this idea.
I hope I don't sound smug- DP still has a long way to go and I would be very naive if I said I was 100% sure that he would never do it again.
There is a charity called Gamcare who have a helpline for family of gamblers (as well as gamblers themselves), I think it is a 24 hour line. I have found them to be really really helpful. You will find their number if you google them.
I will check back to see how you are doing when I get the chance, thinking of you, stay strong.