If you are an artist and you seldom sell anything you made, despite trying to, think about this for a moment. There were hundreds, maybe thousands of people that could have bought Van Goghs, Monets, Cezannes and works by any other master painter you care to name, at very reasonable prices, but didn’t.
Think how foolish the people that were offered these masterpieces actually were for passing on the offer, when each canvas went on to appreciate so much in value. Aix en Provence’s municipal art museum can’t even afford to buy a painting by Cezanne now, when he practically couldn’t give them away to his home city, while still alive.
It may be that your body of work, if you have put your heart and soul and best skills into its realisation, is of potentially huge or at least significant value. The chances are good, if what you do is original and unlike other artists’ work (less so if lots of artists paint in your style). Your chances improve if your own unique style is in evidence throughout your body of work, develops over time and if there is a story behind the works that is somehow told through your works. If your body of work is unprecedented and your life as an artist is in some way interesting, the chances of your art appreciating increases. What matters is that the story and the work are remarkable.
In the final analysis, if all the rejection and discouragement is, in the fullness of time, turned into acclaim and appreciation, isn’t that an artistic life well lived?