I'm really sorry to hear that your art shop isn't doing as well as you'd like
If it helps at all, there was a time when I wasn't pleased with my art (and honestly looking back at some of the art I've made even in the last few years makes me cringe lol). I've been practicing and stusying for years, that's the only way I can explain my level of talent w art. It just takes patience and dedication to become a good artist. I personally really like the art that you do, and it's upsetting that no one else will give you a chance. But if you're willing (and able ofc) to out the time in to practice your art I bet it could be really awesome!
Also try not to compare yourself to others; instead maybe you could study their art and try to apply it to your own drawings! That's how many great artists learn, after all :3