Issues as the player.

I started playing maybe about three, possibly four years ago. I've come a long way since then, I understand my roles in lane (Primarily a jungler, secondary mid lane) and what my champions do. Of course there is always room for improving and that's okay... The problem now is that I can never feel like I'm able to keep up. I know my strengths, weaknesses, what to build, but it's never enough. No matter what effort I put in I'm not good enough to gank, I'm not good enough to fight, and I can never get kills. I can get killed and maybe assist but I can never land an actual kill and rack up gold. I've been told that "Maybe League isn't for me," but that sounds kind of dumb. I feel like if it wasn't for me then I would have realized that a long time ago and quit, and I clearly want to do better. I can never engage properly with Yi or Kindred, my Ahri and Veigar are more or less secondary supports and pose little to no threat. It's like the enemy is constantly a step above me and no matter what work I put in it makes no difference. I watch people like Foxdrop play and I learn from them but it's never enough. Something has to be wrong but I can't place a finger on it. I do know I'm easy to push over, if I'm blamed for something I can't help but get tilted or feel like my lack of skill is bringing the team down, thus lowering my morale.

Just not sure as to what I'm doing wrong or if it's simply my mindset. Thoughts? Thanks...