No experience with GC but with youngest son who was 30 at the time. DS wasn't living at home and we had a call from him from hospital (where he was detoxing), asking for help . We brought him home. We tried the GP who was absolutely no use at all. The GP just suggested he went to AA. We were so desperate for DS and dealt with his struggles for a few weeks. He really wanted to stop but we could see how hard it was. Eventually, we took out a big chunk of our savings and paid for rehab. That was 2 years ago. He has been sober ever since. We know there will be times he will struggle in the future but he has been given coping tools. We are not complacent though and worry about his future, but at least DS now believes he has a future.
Personally, I think the alcoholic drinks industry should fund rehabilitation centres from their profits. My DS didn't ask to be an alcoholic, no-one should be refused treatment if they really want it.
I found the AA message very grim, also Al Anon, the family support group seemed to be about coping with an alcoholic, not about helping them get and stay sober. You could look at the SMART literature. I found that gave me some hope in the early days.
You have my deepest sympathy.