FPS issues after 4.20 and still happening on 4.21

I don't get it, Riot says when the new SR comes out even toasters will run it better, and it did... for awhile. patch 4.19 increased my frames by about 10 making it average about 35-45. then when 4.20 came out... boom. my frames are 15-25 average. everything is on the lowest of low, no sound, no hud animations, i updated all my drivers, e.t.c. every time I auto attack something my game freezes up for about .5 seconds and it makes the game unplayable, same thing when I cast a spell on someone or something. I have sunk A LOT of money into this game Riot... own 4 legendary skins, which alone comes out to $80. I don't even know how many skins I have all together, or how many champions I bought with $$$. I love this game, and now I can't even play it :( I don't have LoLreplay so its not that.... I just hope you guys fix this... because honestly, this is total BS. I want to play again. Please don't just comment, "get a better PC" I'm working on building my own, but I got bills to pay so that obviously comes first.