Watching a loved one die is a very difficult thing, slipnslide - both emotionally and physically draining. We don't have to reach for booze to cope though. If your FIL is in hospice, there may well be a support system available for you, also. Ask the caregivers or the hospice social worker if there is someone you can speak with.
It sounds as though you need to strengthen your plan for recovery - put things in place so that you can say no to booze in difficult situations and other triggering events.
There is a very good SR thread on the topic of Plans. I will post a link in a minute.
*****
As promised:
https://www.soberrecovery.com/forums...highlight=Psst (Psst...wanna know why I'm always recommending recovery plans?)