What exactly would you be doing at the dealership? Sales, or something that has you behind the scenes like detailing cars or paperwork? I think if you have already tried it twice and it hasn't worked out so well, that maybe you should look for something else.

I don't think your worries are ridiculous at all-but if you're already in a tough place, putting yourself in a position where it's possible to feel rejected/loser-ish/a failure, probably isn't a good idea.

What other skills do you have? Maybe we could help you with other career ideas, rather than something that's a known trigger for you.