hey bro, i know the feel. i tried to climb out of diamond 5 for several months and now that im finally d4, i want to climb out of that aswell and its really just my slow learning curve that makes all this so tough ; )
its the same for you. you just seem to not learn very much from each of your individual games. same as me. i have TONS of games played this season and im STILL d4, tho i can clearly see how im getting better and better every week, even if its just small steps.
really keep thinking about how you can improve. i would say "read some guides" and "watch youtube videos" but i sadly have to say, 99% of all guides ive ever read are completely controversal to my own experience with league and i would just say they are wrong.
its like LCS commentators and analysts, they explain stuff but what they explain are things that dont really matter. they totally leave aside, possibly out of lack of knowledge, the really important things, so people dont actually LEARN anything from reading guides/watching LCS but they rather get thrown a red herring, a path that leads them AWAY from learning the game rather than teaching them.
so, what i would reccommend to you is to watch very carefully your own plays.
and i wouldnt even say "look at your mistakes" because that will simply end up as "oh yes i got caught here, that was my mistake. next time ill just not get caught".
that never works, "im not getting caught next time" is not a strategy or a mental concept. its simply nothing. "my mistake was that my nexus got destroyed. next time ill jsut not let my nexus get destroyed so i wont lose". its not something that teaches you the game.
the mistake is not that you got caught, the mistake is the MENTALITY, the IDEA behind the entire situation you created in which you got caught. if you can analyze your own brain and see the things you do and the situations you create for yourself, be it trades in lane, ganks or teamfights, in which you dont leave with the optimal result, as mistakes entirely.
you traded in lane and you got ganked. the problem here was not that you "shouldnt have traded here because risky" but rather you should ask yourself: to make THIS move, what do i need? then make a list in your head or in a text document of everything you need for this trade to go well. vision of all enemies or at least knowing their position, your cooldowns and damage, his cooldowns and damage, summoners etc.
for ALL situations in which you dont leave with the optimal result (which are ALL situations basically) think to yourself what an optimal result would be and how you can realize it and what you need for it. then play accordingly and learn the right mindset.
this way you can actually teach the game to yourself on every elo and win LCS instead of reading guides from goldplayers who have no idea what they are talking about.
also: the ONLY guides i can recommend, not because they are from a pro but because they just really make sense for myself, are the ones from crumbzz on youtube.
https://www.youtube.com/channel/UCm05X6pqXnwUgZBa-kdr-cg
here you can find them all.
if you have any more question, feel free to ask.