Hi, I'm the addict, more than twenty years of active addiction and currently 3 years of no gambling.
It's terrifying and relentless, I've turned into a master liar and manipulator. I've damaged by health, physically and mentally and have had multiple fresh starts and bailouts.
Nothing ever helped until I was ready to face into the consequences of my choices, once and for all. It never felt like I had a choice at the time but ultimately I did.
I'm sorry you are facing this, I'd recommend credit reports, with alerts and visiting gamcare, there is a brilliant forum for friends and family, look out for post by cynical wife, lethe and merry go round - very helpful posts.
Finally do not believe a word he says, go only by actions.
I would not choose to be in a relationship with a gambler.
I'm sorry you are facing this but please do more research and fully protect yourself.