Minecraft my mouse acts wired?

Ok so my minecraft acted all fined a while ago until i went back to play minecraft again and suddenly when i press w my mouse goes up and i can't see even if i look down it forces my mouse to go back up which never happened before it never did that before what can i do to fix this?

Added (1). oh i forgot to mention that when its out of minecraft its normal

Try checking the settings to see if your controls were changed… Comment if you need further help

I had the same exact problem! 2 options will help: get the new update of your computer, windows, mac thing, get any new update, or the other is you have to delete and redownload MC. Save all your IPs to a list, and you may have to redo your mods. It has only happened twice for me.