It won't read! please help

my ps2 won't reada lot of my disks. it will read audio and playstation one disks, but if i put in a dvd, it says that it can't read it, and when i try my ps2 games, it will go to the browse screen and say reading disk. then, sometimes if i wait an hour, it's still trying to read it, sometimes it will show that it's reading the disk, but then when i tell it to play the disk, it just goes black, sometimes shows the usual playstation 2 logo, then goes back to browse. i've tried a lot of things. i've tried wiping the scanner with a towle (it's not easy. i have one of the big bulky ones) cleaning it with a towel that has rubbing achocle on it, setting the read speed to fast, spraying the inside with airosoul, and usuing the auto diagnostic thinger-migig. i've heared of thouse lens cleaners where it's like a disk with brushes on it, but i have no clue where to get thouse. please help me, i've had my playstation 2 for servral years, and it was working perfectly until i tried playing the new .hack game that i got.