That's fair. Just some food for thought, so don't have to reply if you don't wish to, but:

If you want realism, why not just increase your room for error? Like, take up painting, or start drawing on a bigger piece of paper, or draw with a different medium like charcoal. If it's not realism, but skillful drawing that you're after, why not embrace the fact that your drawing will be full of mistakes? There's beauty in imperfection too.

I can't really get behind your point of view. You should never accept you have a limit, because that's how you stagnate. I mean you must have improved the past two years to whichever extent, and there's no reason for that improvement to not continue.

Anyway I'll leave it at that, I don't want to get patronizing. I understand your struggle and wish you the best.