Since this morning my screen has become super sensitive … When I type a message, the letters are doubled or tripled, no matter what manipulation I try to do, it’s super painful because it acts like if I pressed several times. I looked in the settings, I couldn’t find anything to change the touch sensitivity … It took a while just for the settings since it was opening tabs for me when I just wanted to scroll the menu.
Apart from dampness, which I’m sure you have considered, there are a few options you may like to try.
I don’t know if you have tried restarting the phone but have you tried restarting in safe mode. This will disable any apps, and although you will not loose the apps, you may have to adjust the setups for some when you restart normally.
You could try a complete reset but you would definitely loose any custom apps you installed etc. plus any personal media and docs. if you have an SD card installed and formatted as portable, you can move any personal media/docs to that before reseting. If you restart with the SD card inserted never be tempted to format the SD card as internal storage as there are numerous problems associated with an SD car being formatted as internal.
Before either of the above you may like to disassemble and reassemble the screen as it may not be making suitable contact.