I don't usually like to rant but this is something I need to really get off my chest because frankly, I sick of this people with this behavior and attitude.
As artists, we all have shitty days. Sometimes we have moments where he hate our artwork and might compare ourselves to others. This is natural and there's nothing wrong with that. As long as you're able to calm yourself down and don't let your negative emotions control you and your way of thinking, you'll be okay.
However, I draw the line at people who constantly bitch and moan about it, ignore any advice and lash out those they're jealous of.
I had a friend last year who felt insecure about his art and would show signs of jealousy towards those he thought were better than him. And often times, the targets of his jealousy would be his friends. The first few times it happened, I refuted his beliefs and tried to encourage him and he would calm down and be like "you're right" only for it to happen again. Eventually his habit of getting jealous of his friends and lashing out at them would be turned over to me. He wanted to draw in the Disney style and didn't like his current style and thought it was "shit". So when someone like me, who's style is pretty reminiscent of disney, is an earshot away.... I cant count the many times he would lash out at me or delete art I'd post in a server we were in because he felt insecure or give me the cold shoulder out of nowhere. At some point I began getting fed up with the constant barrage of bullshit and because of that, we began drifting apart. But despite this, we didn't stop being friends until May of this year. In all honesty, I'm surprised I lasted that long but I should've left earlier when I had the chance.
Of course, there were moments where he stopped this bullshit by calming down, drawing ocs and then he was back to liking his art again, but in the year or so I knew him, he'd usually be back to hating his art and lashing out people again in a few weeks or so. Now I'm not saying that jealousy isn't normal and if you get jealous your a bad person. It's a normal thing to experience and heck I've been had bits of jealousy countless times. But you can't let it control you, that's the thing. You shouldn't let it control your thinking and lash out at people because your mind told you they did you wrong, especially to your friends. Yes, there will be times where you slip up but its on you to not let that shit happen again. That's what it means to say sorry. It's "not a get out of jail" free card! You have to actually mean it! You shouldn't expect your friends to deal with your toxic behavior!
If you want to be good at anything, you have to put in the effort and work on it! You wont get good by being a spiteful asshole. I wasn't going to get anywhere that attitude when I was 14. I wanted to a be a good artist but I wasn't good drawing. So I spent the past 5 years practicing and drawing everyday and I feel it's payed off. No one's telling you can't do it. The only one that's telling you your not good and that you'll never improve is you.
And, I know this sounds cold, but if you don't see any improvement despite drawing everyday and get angry about, you should just quit. If drawing art makes you so mad that you lash out at others and tell them to "fuck off", why are you still drawing? If you're going to have this attitude about drawing, maybe you shouldn't have started drawing in the first place.
And you know what's the funny thing about all of this? My friend wasn't a bad artist. His art was a okay, not terrible nor great, but there was room for improvement. As long as he studied anatomy, perspective, flow, etc, he'll be a damn good artist. He most likely wont able to draw in the Disney style but that's something he has to deal with. However, I dont think that will happen if he doesn't stop the cycle of inferiority, jealousy, and feeling better by drawing ocs, he's not going anywhere. I told him something akin to this but he didn't listen. At some point he's going to hit a brick wall and drawing his ocs wont save him this time.
I bring this up because I encountered someone similar to him on a discord server a while back. They ended up getting banned for toxic behavior and I can see why.
I feel like sorta went off the deep end with this discussion but I think you should take this lesson from it. If you're feeling self conscious about your artwork, let your insecurities take hold of you and lash out at your piers. I believe that everyone has the protentional to do be great, not just in art, but in general. But are you going to strive to be better or are you going to wallow in negative talk and let that hatred turn you into a monster?