PF Sense in virtualbox - How to?

Hey everyone!

I'm wondering if this is possible and if anyone has experience

Host: Ubuntu 18.04 - 1 NIC - 1x Public IP 144.x.x.x ETH0

Guest: PFSENSE
Guest: PC1
Guest: PC2

i'd like to see if I can do the following:
HOST -- Pass through all traffic to PFSENSE device to act as a firewall.

PFSense accepts that traffic on the 144.x.x.x. IP and then I run Internal Nat for 192.168.x.x on my PC1 and PC2 (Or any additional servers).

I've done the following:
1. Created a bridged adapter EM0
2. Created a NAT Adapter EM1

I would assume the bridged adapter would be sharing the hostip but I can't get it to pick up on that address - and setting it statically fails to ping anything.

Do i need to forward all traffic to a secondary, internal IP such as 10.x.x.x and then use that as my WAN or is it possible to share the 144.x.x.x IP?

I've been looking through docs but have been unsuccessful so far.
Can provide additional details if needed.

Thanks in advance