Why I'm feeling like I have so low stats?

Hi, at the very beginning when I started to play league I played only with my goldy friends so I was accustomed on low stats due no runes and masteries. I had that feeling when I played azir at one of that patch when he was really low. But now, playing everything, I feel like I'm fighting enemies 2 lvls above. Played mirror match as lucian. We both proc passive with e, hit q and passive. And what happened? He won the trade, he did like 20% more damage then I dealt so I had to e from his q to do at least something. You guess it, I do not have those inhuman reactions and my movement speed is too low to escape his q by just moving just like what happened to me where some middlaner went straight ahead and I missed my q. The most tilting things happened to me was again as azir. I played a zed for a while and everytime I went to kill adc I had to: r, e, botrk, w, and hit all 3 q or I had to waste ignite and sacrife bonus damage from my ultimate. As azir I was ulted by zed, I ulted him but he still hit me with his e. And guess it, I died. Only just by r, e combo. WTF. I can do this combo only when someone tryes to escape with bit of hp. I just don't get it. When I want to win a trade my only option is to prey on difference between all champs. That's also why I hate mirror matches because I have to juke or just somehow outplay enemy to even try to outtrade.

That's really tilting and sometimes I just want to uninstall it.

What's happening at late game I can say pretty quick: Being oneshotted, never oneshot.