I completely understand, octoberpumpkin. This is what it's like for me when I work public jobs, too. I have, however, found some to be worse than others regarding the stress response. If I have to work with the public, especially doing something like cash register, the stress level will be through the roof and I'll be crying every single morning and barely able to eat anything. The last time I had this type of job I wound up with 5 different viruses / infections in the span of 3 months... I just couldn't handle it. Maybe it is social phobia???
Anyway, I had a way better experience at a job that I usually only saw the same people every day, no customers. This allowed me to get used to people over time so it wasn't as nerve-wracking.
What I did at the same time was run my own business half time (which I am now doing exclusively) so I didn't have to be in the public at all for that chunk of time. If you have a talent or skill that you could build up a small business from and work from home even part time, definitely consider that!
Do you think that it is the social aspect that is stressing you out so much? The pressure of deadlines or having to process too much info? Maybe if you could narrow down what specifically is stressful, you could avoid that and possibly have some different job choices that wouldn't be as miserable.