Setting up PfSense as a firewall only

Hey guys,

So I've been stuck on this one for a while. I have a small netgate box running PFSense. I want to run it on an existing network under an existing AT&T router/switch that's already in place. I then want to run my desktops and servers through PFSense so that it acts as a secound firewall and a WoL server. I want the internet to just see PFSense and not the servers and desktops but still pass traffic. I know the best option is to run PFSense before the AT&T router, but I need to leave that as due to some things.

I was able to select PFSense in the AT&T router and select port forwarding and bridge it over to PFSense. I configured the WAN and LAN and I then followed the setup wizard. Added DNS server IPs, added the new static IP that AT&T box generated when I selected port forwarding, and created rules on both the WAN and LAN to pass traffic. Yet I have max 20kb/s. So my devices see internet just so little no modern site will load.

The videos I watched all seemed to work after standard setup and wide open rules(just to test speeds) but in not sure what I'm missing.