Well for starters your pfsense box can't have the same IP as your wireless router.
No everything needs to be on the same network (ie 192.168.1.x) with the same subnet mask or else the boxes wont communicate with each other.
Try the following:
I'm assuming that your wireless is working as a DHCP server?
If so keep the ip of the router as is, set an ip pool for your DHCP server on the wireless to run from say 192.168.1.32 to 192.168.1.255. with a reservation of 192.168.1.1 to 192.168.1.31 for fixed ip addresses.
Then on the pfsense box, set a fixed ip address on the NIC picking up the wireless (usb wireless adaptor?) to 192.168.1.2 and then set a fixed ip address on the NIC physically connected to your pc to 192.168.1.3
Set the firewall to allow DHCP and DNS services through in both directions.
Set your pc to dynamic ip address from DHCP.
Make sure all your interfaces have a subnet mask of 255.255.255.0
Then you should be able to "see" the wireless AP from the pfsense box and it should just be a case of setting up the firewall to allow whatever services you need the PC to have use of over the internet.
Hope that's of some help.
