Nimue
Auror
I think part of the issue is with how to handle criticism. The characters we create can be a part of ourselves or come from who we are. If we then receive criticism about how we portray those characters it puts into question our image of who we are as people.
I think this is something that lies close to why men often are nervous about how to portray women.
I like to consider myself a nice guy and I like to think I create meaningful female characters that have their own roles to play. If I write a female character that I take some pride in, that I like, and that I consider meaningful and someone comes along and tears it down for being a stereotype or for objectifying women or some other reason. They're not just saying that I've failed at portraying my character; they're also saying I don't understand women and they're saying that my character is an example of something that I as a person is principally opposed to.
In short, they're saying I'm not the nice guy I think I am.
This is something that I've occasionally struggled with myself, but that I think I've learned to deal with. It's not easy though, and I can see how it's daunting to put yourself in a position where you might have to deal with it.
I think that eventually, you'll have to - whether intentionally or not.
I have utmost sympathy for this, and the thing to remember is that writing with a harmful cultural stereotype does not make you the bad guy. We've all done it, because we've grown up in a culture that has taught us these things from birth. What matters is your reaction to having things pointed out.
Of course the standard criticism-taking steps apply here; evaluate the source and context of this criticism, for sure. But the really difficult part of disengaging from stereotypes is that mainstream culture and all its implicit biases are going to be on your side, whispering seductively in your ear about comfort zones and "getting away with things." How could it be wrong when it's so prevalent? Well, remind yourself that there's a lot of crappy stuff that gets everywhere: practically the definition of a cliche. You're going to have to give it more thought, and take a while to examine your own biases. The first instinct is to defend your writing, deny that there's anything wrong with it, and convince yourself to continue doing what you're doing--which is a writer's immediate reaction to a lot of critique, and I think I'm not just speaking for myself when I say that doing this neeeeever really made me a better writer.
Using a problematic trope when you didn't realize it was problematic is a thing that--and I hope everyone believes this--can be forgiven. But if you continue writing with something harmful after multiple people have objected to it, that shows intent.
The good thing about a lot of these issues is that they can be fixed with the magic of editing and rewriting! Consider what you love about the character, and is it really tied up so tightly with what people have criticized as problematic? Put the character in a new role, give them new agency, shake up their background, try to see them in a new light. Characters can be reborn, and chances are you'll like them a lot better because they won't fall into those particular cliches, and that makes them a little fresher and more interesting.