I'm so sorry for your heartbreak. It sounds a hellish amount of years that you have been in this.
I say this being at the other end of the tunnel, what is in this for you? You don't seem comfortable with the alcohol or the behavior, she does not seem to care about you or your relationship. Why are you holding on so tight?
My deceased AH of 12 years was unmedicated, rapid cycling bipolar. He managed to hide the diagnosis from me for most of that time. He self medicated with alcohol, drugs, and multiple other addictions. I thought I was standing by him when no one else would. I helped co create a nightmare for myself and my family.
I say this as kindly as I can: step back and realise that her choices are hers alone, you did not cause it and cannot control it nor cure it (the three Cs). She has to choose where she goes from here and whether she chooses sobriety or not. The added difficulties of bipolar mean she must choose to get treatment and choose to consistently take medications. Again, nothing in this you can do for her.
I'd gently suggest you take some time out. Take time for self care, take time to reconnect with what you want for yourself in life, possibly look into why you have accepted this kind of relationship. Possibly look into why you think that loving a person looks like what you've been through, and why you choose that instead of choosing someone who can love you in a healthy way.
I know this is a hard thing to go through. I'm sorry that you're in this place. I hope you keep reading and posting in this forum.