Sound like to me the disk has got some dampness in it. It could really make a mess of the heads if so...
Is it a disk containing important data that you can't get hold of anywhere else or is it just a program or game disk that maybe someone here could supply you with...
To be honest if it's as bad as you say then it's best not to try and use it if you don't have a spare floppy drive in case it damages your current one...
