((kate1323))
Lost my first reply....oops. Its late and I'm more tired now, but let me try to summarize:
Try not to think of it as back to square one. Sometimes, as we move forward, we need to take a step or two backwards. It doesn't mean we haven't learned anything, just that we need to keep focused on what it is that we want and be willing to take the NEXT step. YOU are moving forward and can continue to do that --keep the focus on what you can do for yourself.
You have been hurt, and although I am glad to hear he is "working" his program, you and only you can decide when and if you can trust him again. This may take time, but that's ok. Give yourself that time.
Sorry to hear about his grandmother. You said she practically raised him. I would think she still wants him to stay clean --and "work" his program. Now is the time for him, more than ever maybe, to go to meetings, read the BB, and trust in his HP.