How to learn a mechanically difficult champ without going insane

Ok so me, im a very intense person. I also set extremely high expectations for myself. Thats just who i am. So when i invest myself into something, im all in. When i first started i was terrible but i expected that and i didn't have a problem. But now a year later i have a problem. I pick a champ like shaco to learn. And i lose, no big deal, i l