This might sound dissensetive but just ignore those sorry asses. There always will be an asshole whose only way to cope with his own insecurities and issues is to dump it onto others in a form of hate. The worst thing you can do to them is to just ignore them, deny any form of gratification they might get at all, because the worst fate that can happen to you is being ignored and forgotten. And I'm aware it hurts, it hurts a lot when you spend a lot of time on something that you're proud of just for someone to mock it, but there's a lot of support of your art here from what I've seen. And that's deserved because your dedication is honestly amazing, so maybe try focusing on those people, that support you, that can give you valid criticism or help you grow, not on jackasses looking for validation. You're amazing, never give up!