A few thigs to understand that might help you.
First, in no particular order, is medications. Unfortunetly there is no test that says we need .5 of drug A, 1.0 of drug B, and some fish oil and everything will be well. I myself had to try three meds, and then work with the most effective one over the course of 2 years to get the best results. It takes awhile.
Two: Our brains are messed up, we don't understand what "normal" is. Its not like we went to sleep normal and woke up BP. We change over the course of years, and it takes years to find our way back.
three: she has to own this desease, or it will own her. By that i mean you have to treat this bad boy with alot of respect, and understand that when you start feeling that you have complete control is when its going to bite you in the butt. I wake up every day with a huge healthy respect of what this deasease can do. That way i can stay on top of it. Most days i do, some i dont. Thats life.
Failure is an option: Let me just tell you right now, she is going to have bad days and fail. Everyone here has, myself included. The thing is to take steps to limit the amount of damage that failure can cause. Think coping mechanisms, you dont want it to happen, you dont wish it would happen, but you are prepared for it to happen.
For her there will be a period of extreme change in her life. Think getting a nice pair of new shoes, they may fit really well, but they arnt the same as pair of well worn in old shoes that fit like a glove. Thats how it feels. THe meds introduce us to a new "us" that is very hard for people to get used to. And some never do. And many give up and go back to old behaviours, cause they cant handle the new "me".
In the end this is not your fault. You couldnt have loved her better, or made things easier. She didnt do risky behaviours and get BP, or do drugs and get BP, she was born this way. Now whether or not she can find her way out of the "woods" is anybodys guess. Meds help alot, but come with plenty of undesireable side effects that make people quit. There are plenty of good books out there. "Loving somone with BiPolar" is one of them.
The next year, you should try to be as even and level as you can be. Understand its her brain that has turned against her. And even with meds it takes time to find her way back. Now you can only do so much, and if she gets violent, or starts hurting you emotionally and mentally then you have to leave. Only you will know when enough is enough. Trust me, you will know. Hopefully you can help her find her way back.
Good luck Bill