You should not have gateways set on LAN or OPT1. (or possibly OPT2). Only the WAN should have a gateway set for pfSense and that is added automatically for DHCP.
When you add a gateway to an interface pfSense treats it as a WAN and that is not the case for LAN or OPT1.
Additionally whatever is at 10.0.2.2 is not responding to ping. That's probably because it's the VBox NAT host. You should set some the external IP address for pfSense to monitor on the WAN.
Steve