I couldn't fake it for more than 2 weeks even. It's very hard indeed. Not that I wanted to even.
Make sure you take care of yourself first Hadriel. While the probably best way to wake up others is when still posing as a true believer (no anti-apostate guard up) your first responsibility is your own (mental) health, and your family.
Others who can be woken up, will wake up eventually even without our help. So keep it up as long as you can, but please don't destroy yourself in the process.