I'm not going to tell you to "see a therapist." (although I think it would be helpful). What I AM going to tell you is that you were made with a PURPOSE, and that purpose hasn't been fulfilled yet, and so there must be some reason why you are still on this Earth.
You think that ending your life will "show HER," but you'll only be cheating YOURSELF out of some greater purpose that God has in store for you.
You don't need to see anyone, but you SHOULD call a suicide prevention hotline and just TALK to someone. I think they can help you better than people on a divorce message board.