The new game mode: Nexus Blitz is not playable for bad pc's like mine! :(

Whenever i play normals for example i have around 20 to 30 fps and that is okay for me i can still play the game ... kind of ... but in Nexus Blitz i have 25 fps at base but whenever i go around the other players, the jungle , etc. i have 11 - 14 fps! :( Please make some settings for people with bad pc's! Thanks for your time <3