Last Hitting is my Nightmare, Save Me

I absolutely HATE last hitting. It makes me want to claw my fucking eyes out from frustration. I'll see the minion is low, go to auto it--but my champ takes an epoch of animation time and my minions destroy the low health enemy minion within that .5 second time frame. Fuck.

So I see another one is low, okay lemme focus that one. FUCK--it has 5hp remaining, and a castor minion's follow-up auto just killed it.

Like I've watched so many tutorials on how to last hit, but its with champs like Darius, or Nasus, etc, and they just have an ability that will finish off 3-4 minions at once, leaving only 1-2 left to focus on. I've started played Kayle top recently, and her E does a splash damage, and the damage doesn't do equal effect to surrounding minions and early game it's really difficult for me to farm using this method. So I try my melee attack, but I only have 51dmg at lvl 1 and that first wave of minions is important for that lvl2 power spike and FUCK MY LIFE I can only seen to get 3-4 minions out of a wave of 6. And that goddamn CANNON minion is worse, because I'll THINK it's low, auto it, NOPE. 30hp left, aaaaaaand my minions took it.

I've tried clicking on my minion of interest, but averting my eyes to watch it's healthbar drop to try and time an auto just doesn't work in game because I have to watch my opponent as well.

I've been doing custom practice modes and I can't get it. I literally had to take a break because for 30min I couldn't fucking get a "perfect clear" on a wave of minions. Like, I just want my fucking minions to stop attacking. Like, STOP. I got this. Please.

I dunno. I know it's such a "simple skill just aa" but jesus, it's so annoying. I want this taken out of the game at this point it's becoming so encompassing and distracting to me. I LOVE jg, because there's no bitch minions to last hit the monster camps. I'll have more farm as Warwick than any of my teammates by 10min. I want to get better at farming in lane so I can be more versatile but fuckkkk me it's making me miserable. Once my E is stacked up high enough it just isnta-clears a wave, no biggie, but that doesn't actually help me become a better farmer. I honestly don't know how to time this crap out properly, like I feel so stupid because I'm watching my castors, enemy minion health, which minion is taking agro, focusing my enemy lane partner, and ugh... so much. I'd go back to playing support, but watching my lane partner miss farm is equally frustrating as they're 16cs vs a 56cs opponent.