well, I have been under art blocks via humiliation, but I'll go with this ramble instead:
I used to be the guy who thought that all forms of feedback is justified and things needed harsh criticism to improve (even critique towards me)
and after a series of events (something regards to a me making ties with a really crappy person who took advantage of my time, which is a story for another day)
I had seeked someone for help in terms of how to give and take criticim after he had basically hard trashed me and tried to get me into shutting my dahm mouth up and never critiquing him.
and well, at the same time I had also actually payed someone big in the tiny webcomic community to reviewed my comic :U
and to describe it, starting with the person I asked in regards to criticism, as I was trying to figure out something wrong:
they told me, that I am not always wrong, and sometimes when someone trash talks you, not criticise, TRASH TALKS, you don't need to really need to take what they said, which I at first said "heh, okay"
they also said that not everyone is going to take criticism, and I should just not poke the hornet's nest if they refuse to take my advice.
then comes the big man reviewing my comic, got excited and basically I made it obvious that I was going to take every little thing he gave feedback on, and need I tell you this guy was well... I wouldnt say enormous but he had a following, and he reviewed comics a lot, and he litterally just stopped me there and told me:
"you don't have to take everything I say."
a guy who has a following (also a big fan of his), and he frequently reviews comics a lot, and he told me, even I don't need to take everything he says... This kind of turned my world upside down
with those two events, I'm gonna give you this as a 2 cents:
I'm sure people have already told you this, but make your stuff because you want to, don't just make art because of the adoration of other people, and even if your goal is entertainment of others, it's outta loop back to "because its for you"
yes, you can still take some criticism and you definetly should sometimes try and listen to people, but if someone suggests or just tries and force you to make a change that just isnt you, not because the change is to make your art better, but because the change will completely alter the vision that YOU want for your art, and its something you wouldnt wanna do, it's simple, you can just discard the feedback, since it just doesnt concern you at all.
of course if multiple people start calling you out on something, do definetly consider seeing why they feel the way they do, especially if you're an author publishing books!
like its good to look into what people are trying to say so you can improve your art (seeing this is probably your intent), but here's a thought, dont forget to look for things that might just be BS or something you can just reject as a change, since it's not helpful or it ruins your vision, or it's someone insulting you for the sake of insults.
I'd much rather prefer for someone to crash and burn from their foolish ambitions than someone telling them their ideas are bad and them never trying it.
otherwise, don't sweat it! I say just keep making your art! always experiment/try something new, and refine your work
make things because you.