eMac HELLP

My emac is being weird. I am gonna run a play by play with you on what happened. My computer was working fine when i shut the computer down to clean the key board. I unplugged the keyboard and cleaned it then plugged it back in and left it off for a few hours and came back to sign on. It started up fine and then when i went to login to my area the keys weren't working. So i tryed every key and the only ones working were CAPS and ESC and it would recognize only those. Then I restarted it and it let me type my password fine and then i went to hit the ENTER button in the bottem right corner and it wouldnt work so i just clicked the button and it sighed me on. When i got on i went to click on iTunes and the applications folder opened up and had iTunes highlighted but didnt go into itunes. I had to click on itunes in the applications menu to open it. I tried opening my other applications in my dock and the same thing happened. I went on iTunes again and tryed toi listen to a song but when i would double click it would highlight the song then unhighlight it and wouldnt play. I would have to click to play the song. Then when i signed out of al my apps i opned system preferences and it wouldnt let me type anything in the bar. It also would only let me click oncertain things like Xing out, but not going to the previous page. After signing out of everything and just looking at my desktop i started clciking random keys and when i would hit f the file nmenu would open and when i hit v the edit menu would open. It's all really weird and random but HELPP