Genuinely cant climb.

I've been plat five for the whole summer now. I have 400 games which is absolute fucking trash. I play a shitton and im always trying my hardest, but i just can't fucking climb. half the games im getting afk's and trolls, along with kids who just cry when we make one mistake. I have days where i win 10 in a row, then days when i lose 10 in a row. Is this game honestly just getting harder to climb when you're not a smurf/pro who has experience in high elo, or do i need to dynamic queue. I genuinely don't fucking understand how i can play this much and not improve.