Thank you all supermega, shinzo and kejianshi for your kind suggestions, but I haven't solved the problem.
I looked at the tuning cards link but it didn't have the cards I'm using (re and msk cards).
I also tried shinzo's suggestions but it wasn't able to limit. It went wide open to 20Mbps/6Mbps. (I tried both net.link.bridge.pfil_bridge=1 and 0). I've tried different permutations of putting limiters on LAN/WAN/OPT1 or pairs of child queues on both LAN/WAN to no avail.
I also changed cables and added another brand new NIC card and tried different permutations of interface assignments to no avail.
If I disable all the rules (pfctl -d), the upload speed becomes normal (6Mbps), so I think it might a problem with my rules/settings/pfSense (probably not hardware).
I'm open to more suggestions, thank you all again, much appreciated!!