NO, I don't think you are losing your mind. But I do think you are not quite in touch with reality.... Even a well known pros, I mean world renown pros, often say if they made ONE great image per year, they did well. So what's the chance for common folks like you and I doing better than that? It's normal and quite natural to be quite excited about the last shooting and do some "mental exercise" about what you might do with the great image. But, if you are really having that much of anxiety attack over it, it's not healthy. If you are dreaming about great sales, exhibitions, and so on, for every single roll, you need to set your expectation for yourself right.
To me, every "terrible result" is a appointment but also a chance to really evaluate what I did wrong and formulate a plan for the next time. So it's always a mixture of positive and negative. Even great image has something to improve upon. So, I never have a fruitless result.
Do I have long stretch of no keepers? Yes. I'm in one right now.
I wish you learn to relax more. If it's too much for you, set down your camera for a while and do something else.