If you're gonna go, it really is your choice. None of us here can physically stop you, although I wish you would find someone to talk to in your life about it. People on the internet can only offer words of sympathy, wheras people in real life can actually help you.
Get help, now. If not for yourself then at least for the people who would be affected by your death.
I would hope that you reconsider you're actions. Where there is life there is hope of a better tomorrow.
But, ultimately, it is your decision and I wish you smooth sailings in whatever you choose to do my friend.