I was just using the Firefox browser, looking for configurations (no chip on, first use... airplane mode and no wifi) and when I clicked on the cog icon in Firefox the device bugged. It showed me a message saying that the home screen crashed. Now the device boots (shows the LG logo, the animated fox, my carrier logo (Vivo, from Brasil) and the Firefox OS logo, but then it goes to a blank screen (it's actually a black screen with the upper bar appearing, showing it's on airplane and the battery. If I press the home button (or hold it) the phone vibrates, but nothing happens. If I hold the power button appears a menu with: "Turn ON airplane mode" (which is awkward since it is already on, but if I choose it it changes to turn off), "Silence incoming calls", "Restart", "Power Off". Down there is the "Cancel" option. All of them works, but I don't know what to do. Oh, I tried to hold the power, volume up and home screen buttons together when the phone is off but nothing happens. It only turns on when I release the home button. Also, the volume and lock (or power) buttons works and change the volume / locks the phone... What do I do?

The Phone is a LG Fireweb, bought in Brazil.