While I can't quite relate to your lack of wish to make more comics once HoK is done, I can very much relate to that little voice that tells you it's not good enough, and that you're not there yet.
Because I have that voice too. Some days, it's a good thing - it spurs me into improving, into going further, into making more things - but a lot of the time it isn't. A lot of the time, it's that voice that makes me feel as if every page I draw is a compromise between what I wanted it to be, and what I'm actually capable of pulling off, and that my work isn't quite good enough because of it. And I desperately want it to be good, otherwise I wouldn't be creating it.
A lot of the time, it's that voice that makes me wonder if maybe I should just stop drawing entirely, because I'll never be good enough.
And it sucks, and it's really hard to deal with, and a lot of people who don't draw themselves have a hard time understanding just how difficult it is. It doesn't really matter how good we are at what we do objectively - that nagging voice can still hurt us. I'm pretty sure that nagging voice would be there even if I had the skills of a Rennaissance master.
I do hope you keep drawing comics once you've finished HoK - you're making a very good thing, and I'd love to see you make more good things - but if you don't, please don't think of it as a failure. Whatever you choose to do will be good enough.