Hi Steven,
One thing with this addiction… it’s sneaky!!
“…..I’m not naive enough to think I can just flick a switch and stop gambling immediately……”
That sounds very much like the addiction setting you up for your next bet.
Actually, yes you can stop straight away. A blocker for your PC, proper accountability, just carrying the cash you need, using support, getting to GA meetings etc etc. Those are the things that will help you stop gambling and also the actions that might help rebuild trust etc with yoru girlfriend.
People can slip, they can learn from those slips, or not, but gambling again is not inevitable. Don’t listen to your addiction if it tries to tell you that it is.
Keep posting.