Sorry accidently sent my last message before I was done. What I was saying was I walk until I am tired when I am manic and when I am depressed I do the same thing. Except I have to force myself to get up,go, and I walk for a half an hour. I find it helps me. Maybe it will help you. Find a 24 hr gym where you will feel safe and comfortable.
I understand how you feel I have suffered from bipolar disorder for almost 10 years. There have been times were I have been depressed for months and I finally make a life change then I snap out of it. I also have a problem with being manic for days on end and I handle that by going to the gym and walking on the treadmill until I am tired. Sometimes thst
Please talk to your doctor. Every cycle can affect you differently so you might need to tweak your medication. I keep a diary to track how each change in medication feels so my doctor can look for patterns.
Until then find someone to listen to you, over the Internet the phone or person, even just writing free form to get all the feelings out.
Then find a way to distract your brain. Hobbies or exercise help but usually during depression I feel so awful these aren't options. I pick using the Internet to distract myself. Pick an amount of time ( start small if you have to ~5-10 min) and set a task. I read news articles, try to find pictures with a common theme like fishes or ombré or anything, count, addition problems, etc.
Remember that suicidal thoughts are a symptom. I deal with them knowing that I don't want to die, not because we aren't allowed to but because it truly isn't what I want, these thoughts are just temporary.
Good luck!
One thing that helped me was picking up a new hobby. I chose jewelry-making, and I've been doing it for over a year now. It helps me channel my energy into somethig productive (and pretty!). I also like to play music or watch a beloved TV show while making my jewelry so my mind doesn't wander so much.
I would also recommend talking to your doc about your meds not working.