I'm getting jumped in the notes here with "easier said than done" and that's true, so I am by NO MEANS a professional with professional-level art off the top of my head here's some tangible things to help with your frustration tolerance.
It never goes away. Like. Literally ever. "It's so hard and I keep stumbling over it" yeah. Never goes away. For anyone. Keep that in mind.
While you do have to train your eye to get better at drawing, which means you have to look at good art, you also have to stop only looking at artwork made by professionals or people who've been doing it longer than you. Jealous of another 21-year-old whose art is better than you? Block or mute. Lol. It doesn't matter who cares. Jealousy is ugly and you should work on that but feelings like that don't just go away and so if it's not hurting anyone just get that out of your sight. Unblock/mute when you're in a better headspace.
If you can't keep your drawings to yourself then have a dedicated set of artist friends to complain with or hold each other accountable. Preferably people of your same skill level. And no I don't mean a huge discord server full of randos, like, your actual friends, chances are you're only going to get your feelings hurt if in you're some huge buttfuck discord server where people are busy doing god knows what and they either ignore your posts or just leave reacts.
What actually helps ease this is by practicing in bulk. Everyone tells you art is like a muscle and you have to train it constantly, with rest, but constantly. And what this means realistically is you're more likely to learn by drawing something repetitively. Say you're struggling to draw a profile. Don't waste hours getting one drawing of a profile right. If it sucks just start over again. Repeat. Literally the fastest and most efficient way with almost every drawing roadblock is just start over again. The time will pass anyways etc etc.
Confidence is won through effort! Confidence is not so much a feeling as it is the cumulative result of the work you put in. (I read this on reddit one time and never forgot it.)
6. This is a really tough one but you'll have to substitute motivation for discipline.
7. I mean. You don't have to be good at art man. It's fine. You do have to weigh in how much you actually want to get to a certain skill level and weigh it against the amount of effort you're willing to put in. If you're fine where you are that's fine!!! It's fine!!!
