It's hard for me to understand why you don't go to the doctor. Perhaps that's terribly insensitive of me. But honestly, you seem complacent in your addiction. I'm not sure what kind of support we can offer you that can be of any real use if you don't physically get yourself in front of a medical doctor. You need blood work done. Nothing we say or do can help you with that.
Addiction is a horrible thing. And it causes cravings, both mental and physical. It is an incredibly hard thing to face and to fight. But merely talking about your addiction does not fight that addiction. You can talk about it and talk about it until you're blue in the face and all worn out. And nothing will change.
What you have to do is get up the courage to change something about the way you act. Start small at first. Make the committment to stop buying Comet. If you don't buy it, you're not keeping yourself supplied. If you can not do that, than make an appt with a doctor and keep it. If you can't do either of those things, at the very least, make the decision to not keep your supply by the bed. Make it harder for yourself to keep poisoning yourself.
I don't know how you'll take this post. You might get offended. Others might too. But I've been reading your thread since you started it. And once you post here, it's a funny thing, people start to care. I'm writing this because I care. Because I think it's time for you to see a doctor.