Make sure you have an APRC in your pocket, or better yet, an ROC ID and passport, before you even consider the possibility of divorce, either voluntarily or not. Without any of those, you are a sitting duck. A dead sitting duck.
If you haven’t already, start documenting all your contributions to the household. In detail.
Get a safe somewhere, hopefully not under your name. Put your passport, the kids foreign passport, and a stack of cash, as much as you can. Tell a close non mutual friend of where it is. Keep building a cash emergency fund.
All these are measures in case the worst happens. You will be grateful if you do not use them but even more if you do. However, the first point is non negotiable. You need a firm, legal way to stay here without depending on her.