2k Hours Hardstuck Plat - Help!

Hero - Sojourn

Rank - Plat 2

Name - Jolte4

Platform - PC

Replay codes - 22M2X1, New Queen Street - WC8BAK, Route 66 - JWB2WJ, Samoa

I feel like I have good enough game sense to rank up, but my aim is just pretty trash. I don't usually play sojourn like in these videos, I'm best at Soldier I think, but I know sojourn is more meta than soldier and probably better for higher ranks, so I'm tryna improve on her. I want to get to low masters, I think is a realistic goal. But I don't know if my aim is holding me back more so than anything, or if I have more to improve on game sense than I realize.

Also is it normal for your wrist and elbow to hurt after just a few matches? Every time I tryhard with aim that happens to me. I try different postures and try to aim with my arm instead of my wrist but I swear it still hurts.