You're running on a network. Did you do any port forwarding of your modem-router?

So you run as an ultrapeer? If yes is it intentional?

You can disable this thru Tools>Options>Speed>Disable UP cap. & press apply.

I'd suggest you reduce your upload bandwidth to about 70 to 80%. Tools>Options>Uploads>Basic

Do you use the Resume button to continue all your downlds? This can really use up a lot of resources both for LW, your computer & your connection. There's better ways.