I don't think you are out of options. Sounds like you can choose between one of two men, or leave both and look for a partner who is cool with polyamory. Of course people will be hurt either way, but people will definitely be hurt if you kill yourself.
I can see how this situation would be emotionally difficult, but is it really worth dying over? Worst case scenario you end up single, with a broken heart. Being single is not the end of the world, and broken hearts eventually heal. (Emphasis on eventually...)
I almost killed myself over a break up once, and I'm so glad I didn't. (Granted I am here now, but for far different reasons.) I don't doubt that your feelings of desperation are very real, but I think you should give yourself some time to sort things out, because it may not feel like this forever. I don't want to sound dismissive, but for what it's worth, I really do think this is something that can be worked out.