Maciel Hey, what's up?
If you have access via command line, you can use the fwrecovery command to restore access to the graphical firewall interface. Once this is done, adjust the input rule for the LAN network or create an object to release access to your source network and set it to your input rule. If you do not have access via command line, make the connection via serial cable or monitor and keyboard and then repeat the same command above.
I hope I helped!
