I had quit smoking for 103 days. Last weekend I was with one of my friends and thought that I was far enough in my quit that I could have just one for old times sake. Then I had another a few days later, and now I just bought a pack of cigarettes again. I feel like such a failure. I want to smoke so badly again. I don't know if i can start back at day one. I can't go through this all again. How do I start over???? I just want go give up. Any advice from someone who has gone through something similar?