symmetrical keys stop working MacBook Pro

hey guys, i have a problem with my mac which begun yesterday. it was on for the whole night as i was watching movies and fell asleep. then in the morning i took it (it was plugged to a charger all night) and the screen is all black and i cant wake it up. so then i thought maybe somehow i pressed the little sun key and the screen is black. so i pressed the big sun key and tadaaam it worked. however after 2 seconds it went black again so i pressed the brightness key again and it went brighter but as soon as i stopped pressing the button it would go back to black. it looked as if my mac was pressing the little sun button itself. i restarted it and when it was turning on instead of apple icon, an icon of earth appeared and flashed a couple of times. then it told me to type in my password and everything went fine.
however, the problem right now is even bigger as several keys stopped working. the funny thing is that the keys that dont work are symmetrical to each other - left side : escape, little sun button, the button next to 1 / !, and tab . right side : eject button, big volume button, smaller volume button and backspace button.
i havent spilled any liquid on it so i have really no idea what happened.
if anyone knows what is it all about please please help!