I am finding really hard to understand this game

I have started this game about a week ago and I can't seem to understand a damn thing. First i tried playing Miss Fortune, good enough 2 blind matches a B and a S-(which i didn't get a chest for), then i started playing some drafts. HORRIBLE! I can't seem to get more than a C- and also they only way i can get a damn kill is by stealing it. I do not understand what i am doing wrong. I asked one of my friends to teach me a little on how to play the character. After that match i seem to be getting matches where 5 PEOPLE COME TO MY LANE JUST TO KILL ME AND SAY "BYE FELICIA!".

So it was all good and fun till somebody cracked under pressure and decided to play a different role. So i tried junglers. I am not fitted to play a very tanky alternative as a top, or an assassin for a mid, or a damn do-it-all mage. So i saw a jungler that i liked Kayn and decided to play him. I only learned 3 games into playing him that he has different forms when he deals an amount of damage to enemies. In my opinion he seems pretty fun but i can't get a bigger grade than C with him. I do not understand what i am doing wrong

So that was all fun till i saw someone play Kai'Sa. Big mistake. It looked fun so i decided to try her. Instant D- worst play ever. I kept getting ganked over and over and over but from the plays i have seen they were getting ganked too and it seem like no stress at all they just killed them all or used their e to run away. Only my E doesn't seem to be lasting as long as their does and also my attacks seems to do no damage

I am really considering to uninstall this game for good. I just don't want to play with my friend again and for them to feel like an instant loss. I know they don't want to say it but i know they all think its always a 4v5 with me in their game. YouTube tutorials are not helping either. I feel like these YouTubers feel like i have playing MOBAs since i came out of the womb. Honey the only MOBA i have played is BattleBorn and that is more of an FPS than anything. I just sit there staring at a screen feeling the "Why are we still here? Just to suffer?" meme playing in the background while I'm watching this guy TRYING TO UNDERSTAND WHATEVER THE FLUFF CS MEANS. Don't get me wrong the game if fun. But it is just very frustrating to get a loss 10 times in a row and not understanding what the fluff am i doing wrong.

I really hope somebody sees this and helps me cause I am a lost cause. Also I really hope somebody as noob as me sees this and sees the responses and maybe doesnt have to fill an entire book talking about what the fluff are we doing wrong.

Also should i just submit to the thought that i am a total lost cause and i should stop playing for good and just stick to FPS games or should I at least try to get some help