She just turns into a different person completely when she drinks.
This typical of active alcoholics. If you suspect suicide or she refers to it in any way, get on the phone immediately and call 911. There is nothing you can say or do that is going to affect her drinking. What alcohol does is loosen our inhibitions; drunks are irrational people so don't fool around with this. It's serious. My heart goes out to you, I'll say a prayer. God bless.