Greetings!
To be honest with you... There are a lot of days I think that. When I lose followers on my art account, when I don't see much traffic or subs on my comic, when I don't get replies on my instagram posts... I guess that the success of others sometimes gets to me. In the other hand, however, I gave up once, and that was horrible.
A few years ago, a had an art block and I was only able to draw and design on demand, because I had to graduate on college. I felt worthless, below average. I even told myself that I was no artist. Then... One day, on one of my bellydance classes, in the middle of a dance workshop, I drew myself in costume. A regalia that I am still going to sew. Bit by bit, I regained confidence.
Being independant is hard, and most of the times we will collect rejections rather than approval; overnight successes are inspiring, but they can be deceitful; our career is a difficult one, we must do everything we can every single day. It's massacrating. However, it is part of the process. Believe in your artwork --- it is good enough! Our career is hard, but you'll manage to get a place for your work. And sometimes it's not on the first try --- some stories, even when they are great, are not what mainstream culture is looking for. Sometimes it is. It's out of our hands, mostly.
But do not give up. Your art is unique and it has its value, its worth and definitely has the attention of people. Keep doing what you are doing in your pace. =)