Even after 8 years in Portugal (we celebrated last Friday), I still hesitated as I stepped up to the WC in the restaurant.
Some years ago I ended up in the IKEA women's toilet, misunderstanding the 'S' (or 'M') on the door, and I will never forget the look on the ladies' faces, as a I emerged from a stall, having entered an empty 'casa de banho'.
There's confusion, and there's old habits too. Like nearly getting into the WRONG side of the car to drive, only yesterday, even after all these years of driving in Portugal.
Learning a new language and adjusting to the culture is a gradual process!
We need to stretch ourselves AND be kind to ourselves, as we adjust and settle in.