Just wanted to thank everyone here for everything these past 3 months.
At the advice of some of my friends, I uninstalled the game a few days ago. As was pointed out to me by them, I was only stressing myself out even more by trying to rebuild my old account without any help, and basically couldn't get much help due to where I stood compared to them.
(Level 21 with meh MMR + a bunch of level 30s with high-Silver/low-Gold MMR = bad time for all, as I learned from the two times I'd tried it. Small sample size, yeah, but matchmaking's generally iffy when it comes to pre-30s + 30s anyway.)
If there's ever some sort of thing instated in the future to try and earn an account back, I may return to try it. Otherwise, I probably won't post much anymore. I still wanted to thank everyone for being so cool to me over these months, though.
I unfortunately wasn't able to make much of a difference myself. I had one guy add me in-game (on my other account) to tell me he'd read my threads and thanked me for the good advice. I then spectated his next game on a whim and watched him tell the enemy Udyr to kill himself several times in all-chat over the duration of the game, and just in general be a fairly abhorrent person, and it really bothered me. (I should've saved some screencaps of all that, but I didn't think of it at the time.)
I'll try to find something new to occupy my time with. Not sure if anything can potentially bring me the same sort of fun time League used to, though. Especially so long as most of my friends still play it. That's life though; nothing ventured, nothing gained.
Thanks again to everyone who offered me advice and a show of faith. If nothing else, I wanted to at least show that sympathy DOES exist on this board for people who show the effort to change, or at least understand where the fault lies.