What you are describing is consistent with a generalized anxiety disorder. You don’t have to continue to suffer like this.
Life will inevitably hand you new things to deal with. Unless you are willing to live in a cave and do nothing, you need to learn new ways to handle novel situations and to be easier on yourself. If you could do that on your own, you would have done so already.
I strongly suggest that you see a counselor. Cognitive behavior therapy is well-documented as a treatment for this diagnosis. You might also want to try some medication to reduce the anxiety a bit so you will be more able to take advantage of the advice that is offered. Talk to your clinician about a comprehensive treatment plan.
You are in your 50s. With some support, there is every reason to believe that you can make the next 50 years be more comfortable ones.
I wish you well.