Shadow - do you have a pdoc to phone?
I know you don't want to be talked out of it, but I don't think that is true. Else you would not have posted here.
You know you don't want to do this. You want someone to stop you. And I'm right here telling you NOT TO!
Think about all the things you have not yet done in your life. Think about how the people in your life will feel. I've tried to OD, unsuccessfully, and I had to face my friends and family.
They take strain and blame themselves - I know you are not prepared to put your family through this.