Chat resets
Every time I try to type in the minecraft chat it deletes by itself without me pressing backspace and then the minecraft launcher closes and reopens (Not like closing it pressing the x) it closes down as if it were to minimize then it quickly goes back to what I was playing.
Tried a re-installation/checked if any error .txt files have been generated?
Maybe you have a virus/keylogger? try using a free antivirus if you havent already