There are two reasons why you don't upload:
1/ The torrent you seed got no leecher (downloader) at the moment. Keep it seeding, in case someone starts downloading
2/ You are the only leecher on the torrent you download at the moment. Nobody to send the parts you've got already
In addition your Transmission is reported as not connectible (read the earlier posts in this topic about what that means)
The trackers you name (those I know by name), are public tracker. they got much more user and because they haven't a ratio many peers leave after download. That makes seeding easy for those how stay.
To improve the connection of Transmission, make sure you've made an exception in your Mac's firewall for the port set for Transmission's connection and activate UPnP and NAT-PMT if that option exists. Sorry no Mac here, can't help you with step by step instructions.