FPS problems renders game completly unplayable. :(

I love playing League. It's an amazing strategy game that makes you think and promotes a groupthink for Victory. Unfortunatly, for about the past week to week and a half, my FPS rate ranges anywhere from 2-6. The game will start at 6 FPS, and lower with more people down to 2,3, or 4; less FPS the more summoners are on the visible map.

As a result of this issue, I cannot land most of my skillshots, my spells are delayed, and I have no visibility of the enemy team. Also, movement commands of the champion are delayed as well. So, not only can I not land any attacks, but the enemy always kills me.

For instance, I just played a Morde ADC game. As Morde, I could not land my w on an ally. Also, I could not land q as the champions teleported from place to place. Casting my Ult didn't happen either for the same reason I could not cast my w on an ally. No kills at all, just facerolled all game. Another example: Olaf top, last week. Could not land q, again, because of lack of visability. Than a gank happened, FPS lowered even more, and only death comes.

Because of these technical issues, I get flamed by other teammates, for them thinking that I was intentionally feeding, and that I am a terrible player. This technical issue results in a negative experience in gameplay. Last game I was literally told that they would be better off if I AFK, which I didn't want to do because I love League so much.

So, is anyone else having this issue? If so, does anyone know any fixes? If not, is this issue known, and planned to be fixed with the 5.18 patch? To anyone reading this, whether fellow summoner or riot employee, if you have any info on the subject, or any way to fix the issue, any response would be greatly appreciated.

Thank you for your time taken to read this.