To put it into perspective, last act I had a 45% winrate which is REALLY bad, like bottom 15% of players bad.

I grinded valorant really hard trying to get better (well over 300 games). I would play 10+ games per day, but it seemed like no matter how good I was winning/losing was out of my control. I was struggling and hardstuck for weeks on end at a rank that used to be super easy for me.

What I didn't realize was not everyone gets better the more they play. When I played tons of games per day, I didn't care about losing because subconsciously I would think "I can make up for any lost RR later". Now I only play 1-3 games per day, each game and each individual round matters so much more. I don't give up nearly as easily as I used to. When I'm down 2-10 at half, I still try and think of ways to win. It sounds like a small change, but now I have a 65% winrate and I'm around top 3,400 NA. A good mental isn't only essential for you, but it has a drastic impact on your teammates.

https://tracker.gg/valorant/profile/riot/Zermist%231417/overview?playlist=competitive

You can see on my trackergg that I don't carry or pop off at all. I think I just tend to win the rounds that are most essential and provide value when my teammates are relying on me, because like I said I'm playing to win every single round.

Maybe you were expecting more profound advice than "have a good mindset :)!" but the results are what is profound. This is proof that your perspective completely alters who you are as a player. I would go as far as saying a good mindset is more important than your skill level itself.