I have had SIs during my most extreme desperation periods, but I never wanted my life to be over, deep down. Or if I thought I did, it was not rational thinking, but distorted illness thinking. Mine were more "calls for help" than anything else. Though I know death is inevitable for everyone, death seems to me to be far scarier than any pain I would ever experience from bipolar disorder. That's not to say I haven't experienced severe mental strife from the disorder, but I've learned that bipolar induced pain DOES and WILL ease up. Even if it takes five years, five years of suffering leading to any number of years or months of relief ALIVE is better than premature death, in my view.
I've learned that patience is crucial and patience almost always yields rewards. Patience coping through painful episodes. Patience trying to find the right medication(s). Patience dealing with side effects. Patience until I finally learn that some things are not nearly as painful as they seem, or that the pleasures and love that I have far exceed the pain that I feel. If pain seems to persist to a limit where patience and tolerance is just no longer possible, one has to really scream out for help (figuratively or even literally) and demand major action. If that means hospitalization. Do it! If that means ECT or Transcranial Magnetic etc. Do it!
From my years of therapy, I have learned how to fight anxiety to a very good degree. And fight depression to pretty good degrees. Am I always completely successful at fighting them? No, but I get better and better. I'm significantly better at it than I was when I was younger. I have the advantage of age and experience. I can ground myself better and quicker, too. Another thing I've learned from two extremely smart and talented psychologists is that the more you practice coping, and the more you remind yourself that pain will pass, or that it can be managed, the less hopeless things seem over time.