She's had a drinking problem all along....being the life of the party, having a boyfriend, dancing with men half her age, refusing to take a 9 year old child home, sleeping in bed with him and urinating in bed. None of this is normal.
You're most certainly not to blame for any of that. Stay away from anyone who tells you you are.
Are you in a position to leave home? If so, you really need to. You need to follow your own path, make your own life, make friends with people who behave normally. You can't fix these problems for your mother. At this point, you can only save yourself.