Which champion should I play? The champ I like more, or the one that's better for my mental health?

I used to play only Kayle support. It was fun, and I like it. Not a meta pick, but it worked for me. When Yuumi came out though, I switched right over. She was just too cute! I love her gameplay and her character. But the trouble with Yuumi is she's very team dependant. Which isn't strictly a bad thing, just, sometimes it can be bad for me. Because I have to attach to my teammates, I'm more aware of what they're doing... And when they screw up. I've always thought of myself as a very calm person when playing league, but when I'm attached to someone as Yuumi and they do something stupid that gets us both killed? Sometimes I end up yelling at the screen, something I usually only do on bad days. I thought I was just testy because of a recent change in antidepressants, but yesterday I played a game where Yuumi was banned, so I went back to my old Kayle pick. And it was a very relaxing game. Don't get me wrong, I still love playing Yuumi, and as a bonus, my winrate on her is a bit better than on Kayle. On Yuumi my winrate is 56.7% while on Kayle my winrate is 52% I'm just worried that playing Yuumi might be bad for me? I don't like getting angry