Cur Parkour Lag

Is there a way to stop the Undergrowth Ruin dungeons, normal and corrupted, from freezing my computer? I love the parkour and I find it a joy to do, but whenever I attempt the escort and parkour sections my pc keeps going to 0 fps and not going back to normal for several seconds, which usually results in that section being failed. Please, if someone knows tell me! It's at the point where I can't even finish the dungeon because the instant I jump onto a slime pad I freeze and can't move, sending me out of bounds and resetting. Any help or advice would be appreciated!

 

get a better computer

 

The way I fixed it:
Switch to minecraft 1.12.2

Already tried that?
Install optifine (and set everything to lowest settings)

Otherwise, no idea
(Maybe also try to close out application running in the background, like discord and steam)

 

Just type fps mods and download everything