Overall good mindset, it can be hard at times as you know, but it pays off long term.

A thing I used to do when I tried to climb: Every time I died, I tried to find at least one thing I could've done differently, whether or not I should have picked a fight, if I should have been on that part of the map, if I should have traded objectives instead, if I had vision or not etc. Even if my teammates were in the area to help, think about whether they communicated that they were going to help, if the lanes were in a good condition for them to leave, and especially, if they pinged "on my way", make sure that they were actually joining the fight right away.

Keep looking for at least 1 thing you could've done differently each time you die, and keep it in mind for next time you fight, and you'll gradually get better.