You'll find info & further links for using a proxy here. If that's no help, use the forum search to look through old threads.
http://www.gnutellaforums.com/showth...ighlight=proxy

If your internet's crapping out when downloading, try:

Disabling ultrapeer capabilities (tools > options > speed).
Disabling iTunes sharing (tools > options > iTunes).
Reducing upload & download bandwidth a bit (tools > options > downloads & tools > options > uploads).
Limit your downloads to just 1 or 2 at a time.