Just to understand it right. You and your friends all can run the game easily with 100 fps. But just one of your friends gets only 1 fps.
So do you guys have comparable hardware. Or what hardware is your friend running the game on?
Also I could advice to try out some performance mods:
https://optifine.net/home (isn't allowed to be added to a modpack if I remember right)
Also it could help to uninstall Java/Minecraft and make a fresh installation.