I did go through that at some point, but eventually I realized that what I like is the process of leveling up. It wouldn't be an achievement if I could just be better immediately. Like, I wouldn't play RPGs if I started out at Level Godlike because what's the point of running around killing everything without any resistance or challenge? So if I woke up and could just do art effortlessly, I'd quit. It wouldn't be fun any more.
The struggle is the interesting part. It's like you're handed this fiendishly complicated puzzle and at first all you can think is that you want to solve it NOW NOW NOW. But you can't. Then you start looking around at all the other people solving it and you compare yourself to them and it becomes all about how other people are ahead of you and you're a loser and blah blah useless insecurity. And then one day you actually get into the puzzle and all that other bullshit falls away and you're like "Wow. This puzzle is *really freaking cool*. I wonder what happens if I wobble this bit?"
If you hate the pen tool then its as simple a solution as not using it. Also perfectionism isn't healthy since it can never be "perfect". If you want to learn what you want to learn you kind of have to be alright with mistakes and the occasional horrible drawing.
I just beat myself up and keep going whether I like it or not. I have to, or I'd starve. Even if I'm uninspired, I'll do studies of simple subjects to keep my hands trained, and eventually I'll get back into enjoying it again. It probably helps that I'm a masochist in nearly every sense of the word and am fueled by self-loathing.