Hello ....
Self-diagnosis is really risky - sometimes even dangerous. You didn't mention seeing a therapist, psychologist, counselor or whatever you want to call the person.
I've gotten the impression that you're predicting or preparing for serious illness. Please don't do that! Try to think about gratitude. That is, what are the things in your life that you're grateful for!
If you don't have a serious chronic disease, try to be thankful for that. Take that from someone who has three different serious chronic diseases that are not cureable.
Please do find and see a therapist. You probably have more to be thankful for than you realize. Try to replace your negative worry with some positive facts - ands then some fun!
Peace and wellness
Rob & Gizmo