I'm fairly similar in that I'm hard on myself for mistakes I'd definitely let slide from other artists. I think one of the big differences when drawing comics is that you don't read your own comics like you read other people's. When you read somebody else's comic, you probably don't scrutinise every panel in the way you do with your own because you're busy being wrapped up in the story.
Something I find helps is getting to know professional artists, or try to watch or listen to things like podcasts or videos or find blogs where an artist talks through their own work in a casual way. I like Tom Siddell's youtube channel as an example of this. He's a really down to earth guy and openly will say "I don't like this panel" or "I don't think I got this across well at all". Pros make mistakes and use shortcuts all the time, and you can feel a lot more comfortable with yourself being aware of that.
Another good idea is to revisit comics you haven't read in years, but when you were younger you thought were amazing, unapproachably professional. Chances are you'll discover mistakes and wonky drawing you never noticed when you were less experienced and artistically competent yourself.
The most important thing is you have to forgive yourself for mistakes. The vast majority of people in this world, like people you'd meet on the street, cannot draw as well as even a semi-competent artist, and if they see you drawing, they will react like you're doing magic. There are wonky drawings all over the place in published works, or even perfectly proportioned drawings that fail to capture what the artist wanted. In the end, the illustrator had to hand it in for their deadline and forgive themselves, and those imperfections are often what gives the work life and charm.
