I sold off all buildings and abandoned Britain, Iberia, Eastern Europe and Northern Gaul. WRE Rebels arose on turn 3. I assembled two large armies from evacuated troops in Iberia and Northern Gaul and attacked and pillaged my way back to my borders, letting the captured cities revolt again behind me.

Due to massive looting cash and reduction in forces from revolt, I was in the black by turn 5-6. I then replaced all garrison troops in non-frontline cities with peasants and began building trade buildings. I have stabilized there and have been earning 3-5k/turn regularly since then. Once my cities are built up to fully exploit trade and increase income, I will convert the fringes to Christianity and re-take Gaul and Iberia.