This downloading is not normal
Try deleting your preferences folder, instructions are here
http://www.gnutellaforums.com/showth...threadid=36420
If this doesn't help then I think you should run an AV scan. You might have picked up a virus. Set your maximum downloads to zero & see if it still happens (tools > options > downloads. Apply after you change it).
For your library problem, do you mean that there's no library tab? View > show/hide & tick Library will fix this. If you can see the library tab but can't open the page, deleting the prefs might fix this. If this is no help, then possibly your computer is infected.
Here's some info on virus probs
http://www.gnutellaforums.com/showth...threadid=41432