Ayy - congrats! Finishing things is hard. I think the concept and artwork are dope.
I feel you about how much public response can fall short of our expectations, especially if you've relied on friend's and family's support for that last push to finish. It can be pretty disheartening to experience that sort of whiplash.
But that's the thing about putting out complete works - once you've finished it and put it out there, it'll (usually) continue to exist somewhere for people to look up. Maybe that'll be after you've published your n'th completed project, or maybe it'll be after they saw a cool drawing of yours that they followed to your social media. Who the hell knows? All I know is that now that it's out there, there'll always be a chance for it to catch someone's eye. You just can't hold your breath and try and wait for it, I guess.
Anyway, congrats again! Keep going! (also keep posting here!) :D