Something is wrong with my macbook pro

What is going on with my Macbook Pro

Ok something major is going wrong with my macbook pro, i dont know where to start. A few weeks ago it started to get slow, the harddrive is usually very heavily full with mostly music so i freed up allot of space.

It did not fix anything, and things were starting to get slower, i use adium messneger and skype, sykpe started to get glitchy like i could not click the red X to close the program or minimize it i had to force quit it.

My adium would simply not start up anymore, i reinstalled the 2 of them too! and nothing. So i started to think maybe something is up with some system files or something im not that much of a techy, so i reinstalled my OSX and it got worse!

Anytime im on a website and when i type anything after a few seconds depending on which key (letters) i press the screen will either scroll to the bottom of the page usually when i press the spacebar or it will back up to the previous pages usually straight back to google everytime after i press back space, i basically had to type all this out in notepad so i could post it here!

And skype does not even open now either im really worried about my machine what could this be from, i reinstalled OSX snow leopard again btw and still nothing

Please can someone help me

Shane

Im going to keep at this for a bit and try fix it

check your Console Logs.