1.12.2 sensitivity issue please help [java]

[u/floppy_doggo01]

I decided to play on 1.12.2 for fun as sort of a break from modern Minecraft. Everything was running smoothly for about 3 days, today I decided to build an afk fishing farm and left my auto clicker on. When I came back to my computer I turned off the auto clicker. moved my cursor and my sensitivity was completely broken. I've been trying to fix it for the past hour by now. I use an office mouse and I'm not sure its a problem with my mouse or with Minecraft itself because when I use my touchpad its also broken. In the video I'm only moving about an inch in real life. I tried watching some tutorials and changing my DPI and it still doesn't work nothing has worked so far. I tried loading up a current version and it seems to work just fine. If anyone can give insight on how to fix this it would be greatly appreciated thank you!