If you can ping only local machines pfSense probably has no default route. The WAN interface and DSL modem have public IPs but they are still local to a pfSense interface so it will have a route to them.
Have you set a gateway on WAN?
If you go to System: Routing: Gateways: Is the WAN gateway set as default?
Edit: Just noticed you can ping 188.8.131.52 so forget that!
It's probably a DNS problem if you can ping IPs but not URLs. Do you have those Google DNS servers set in System: General:?
When you try to ping google.com what is the actual error message? Can you ping from the pfSense VM?