I feel this way too at times. Its like a big emotional circle of fear, depression, and guilt. You know how you could look at this behavior in a positive light though...you clearly see how precious life and health is. So try not to let this fear stop you from living your amazing life. Everyone has these fears, its just about how you process them is all. Break the circle. It probably seems so hard to get over now, but it will get easier because you are dealing with your fears. For me, every emotion is intensified when I am depressed. What helps me when I feel this way is writing down the things I am grateful for every morning. My health always being one of them. I also write down what about my life I love, and what makes me happy currently, even the simplest things, and then I try to be around/do those things. You could also make some small goals. Write those down, and try and occupy your mind with getting those done. This helps me.