I think I can offer a perspective from the other side of things... as someone who DID give up when my comics didn't get any subscribers... twice.
And it basically just came down to... making comics isn't my passion. Sure, I love drawing, and at one point in my life drawing comics really helped me, but that was years ago. And if I'm being honest, the only reason I started drawing comics again was because I found this site and I thought it would be easy to become "famous" (and maybe make money).
My passion is writing, and I'll continue to do that even if I never become famous, just because I love it. If you're really feeling discouraged maybe you need to take a step back and really think about why you're doing this. Is it because you truly love it? Then you'll persevere, and you'll get better, and hopefully one day you'll have a lot of viewers. If it's just to be famous or to make a living with it, then maybe that's something you need to consider.
Also, I thought this subject was addressed brilliantly by a youtuber:
"All art does have an audience, even if it's just an audience of 1. You. If you worry too much about getting a huge following you may not feel as fulfilled by your art as you could. And if that's all you care about then even your audience of 1 won't enjoy the finished product." (Magicturtle643, "Art Doesn't Need an Audience!")