Depending on the layout of your space and how it's constructed, fishing cat 5 through the walls using fish tape might be relatively easy. A quick search will fi

Depending on the layout of your space and how it's constructed, fishing cat 5 through the walls using fish tape might be relatively easy. A quick search will find you guides with the details. However since your place appears to be cursed for networking I'd try running cat5 outside the walls for a while first to make sure it actually behaves as expected.