maybe you need some help to get through all this. Sounds like a lot of changes and stress to me. My big advice is to see a doctor and for the fears a psychiatrist. The alcohol and cigs probably just masked some larger issues. Just my uninformed guess here but getting good help is never wrong.
First of all, congratulations on quitting the booze and nicotine! They are extremely difficult to quit and you've taken both demons on at the same time. I wonder if you perhaps shouldn't have attempted just one before wrestling the other? Maybe this "double whammy" is what is messing with your head? It has been a relatively short time that you've been "clean" and while nicotine is out of your body in three days, the psychological and emotional "addiction" can take a great deal longer to get under control. Four days into a nicotine quit is when the going really gets hard. Alcohol, to the best of my knowledge, doesn't stay in your body very long, but the addiction is intense, the mental battle for both of these drugs is non-stop and relentless. I would have suggested you get a good physical, but it sounds like the docs have checked things out and have given you a more or less clean bill of health. I hope you are under the care of your doctor while you are going through the detox phase of your recovery, he/she can give you medications that will make the process somewhat easier. I hope you are also getting support from a group like AA and the American Cancer Society.
I believe that many of your anxiety symptoms are related to the withdrawal process and this is why I think you should be under the care of a qualifed doctor who understands this process. Your body and mind are going through hell right now and you should not be attempting this alone. Have you posted over on the Alcoholics Forum? I know they would offer you a great deal of support and be able to answer many of your questions about the things you are feeling better than I've been able to. But please feel free to post here as often as you need for support for the anxiety that this brave attempt is causing.
I wish you great strength for this battle.