You are NOT a lost cause! You are a person that is going thru a hard time right now. We have all been there. "Why can't I just stop?" I said the samething about me the samething about my mom. Like you said, you are sick. It's a disease and it sucks us in and sucks the life out of us.
Going to your doctor is a wonderful idea and so is the psychiatrist. You can beat this and you will beat this. Keep posting here and reading.