Any advice for someone who has not done anything other than work in the last 15 years (weekends and vacations spent home indoors etc.)? I spend my free time obsessing how I'm pissing away my time on this planet and at the same time terrified of doing something else.
Start small and spend your weekend and vacation not indoors? :) if you are really afraid of getting away from a job then just bringing some reading material for the job outside could go a long way
Looks like you know what there are some problems (at least in your POV) with your current life.
Take a sabbatical[0] and try to understand what do you need to be a happier person.
[0] in my case it was a sessions of a late night and beer talk with a people who doesnt't know me, but was greatly supportive of my situation (beer hleped there). YMMV.