I'm so sorry to hear that you are considering suicide.
There will not be oblivion, but you can't expect everything to just be suddenly OK after dying. It is not a get-out-of-jail free card.
But that's all besides the point. I know that you have gone through a lot, but you need nothing more than to see a psychologist, urgently. Honestly nothing is worth you ending your life over. Things change, and usually change quite quickly. You have potentially 50 years in front of you. Things will get better.
You just need to see someone about it and talk things through. It'll be nice to talk to someone who has an objective perspective.
I will be praying for you. Please keep us updated.