health obsession

Hello my name is Mikey I have severe ocd and panic and stress!!!!I am scared to the brink of a breakdown of having a fatal disease!! I use to drink alot of beer!!! But have been sober for three months. I have been exercising and trying to eat right for about a week. I see my doctor almost every month! In may I had a liver function blood test all the enzymes were high!! My doctor orderd a complete hepititis panal and a ultrasound. The hepititis panal was ok the ultrasound showed fatty liver and gallstones. two weeks later one enzyme had returnd to normal. Another one was almost back to normal and the third is still high but I have been told that everything is ok. My question is I am now afraid of stomach and colan cancer I have been constipated alot of times and I have been having loose bowel movements for a long time!! No blood in stools that I can see. I have been told by a pharmasist that stress and tinsion can cause chronic constipation and diarea I weigh 305lb and evan though I have the eratic bowel movements I have gained weight. If it was cancer I would be droping weight fast right please tell me that I am right please!!!!!!!!!!!!!!!!! I am terafide!!!!!!!!!!!!