You're not alone. Many of us have taken on the responsibility of living for another person as their disease swirls them down the drain. What helped me was the three C's - I didn't cause it, can't control it, and can't cure it. Learning about enabling, setting boundaries, and working to let your loved one experience consequences of their behavior can't cause them to become sober...but, at least, in my opinion, you can at least not contribute to the disease (hide them from their horrible behavior - fix things for them - make excuses for them - ya know, what we loved ones do - they wrap around the alcohol and we wrap ourselves around them). We can help the denial stay in place by participating in that as well.
My best advice is to read on this forum. Consider attending a 12-step group (such as Al-anon). Although you can't figure out how to fix your loved ones behavior, you CAN figure out how to heal yourself. The disease is like dropping a grenade in the middle of the family. You very likely are suffering from the damage of the explosion and need some help yourself. Take good care of you. Live by example.
Just my two cents - take what you like and leave the rest.