I think it's quite understandable to fear for your future based on the evidence presented.

I find the worst thing about such fears is the way they can detract from my ability to take useful actions.

I find one helpful method is to re-frame my thinking. No, I have no guarantee that everything will turn out "all right" for any given value of that. However, so far I have been through more than I once thought I could cope with. Am I unscarred? Certainly not. But I have work that I enjoy, people in my life I love and who care about me. I have food and shelter and access to reasonable medical care. I'm in a lot less physical pain than I was a few years ago, and more importantly have learned that pain, while unpleasant, is more tolerable than I had imagined. When I can appreciate how far I have come, the unknown territory of how far I have yet to go is less daunting. Sometimes if I'm really struggling I turn this into a written exercise.

The other thing I find helpful is to distract myself by getting really stuck in to work, to the point that worries about things I cannot control or predict get crowded out by more immediately topical concerns. I'm not certain this is wholly beneficial, but as much of my work is project-based it is moderately self-limiting. A variation on this technique is to go on holiday, if I can do so without seriously endangering work. The change in routine can be disorienting but sometimes seems to encourage me to think differently, perhaps because in an unfamiliar environment I must pay more attention to my immediate surroundings.

These are more pragmatic responses than rational, and your experiences may vary.