Game slows down and buttons are unclickable when changing render distance

i was playing minecraft and I changed my render distance to 32 to see how it looked. it was working fine until suddenly it started slowing down and I went back into the menu to change it back, but it was so slow that it wouldn't let me click anything so i had to force quit. I tried reopening it, but it got stuck at the "Downloading Terrain" screen.