Andrés, this is exactly us. My partner is French, we met in English, and French at home felt like a role play. What worked for us was one small fixed thing rather than switching everything: dinner in French, the rest of the day whatever comes naturally. It's only an hour a day, but it's every day, and it didn't break the way we talk to each other. After a few months dinner got easier, and now we drift into French at other times too, without deciding to.
Honest question for people with a local partner. Giulia is Italian, and you'd think living with a native speaker would make learning Italian easy. In reality we met in English, we fell in love in English, and switching to Italian at home feels strange, like we're pretending to be different people.
When we try, I get frustrated because I'm slow, she gets frustrated because she has to repeat everything, and after ten minutes we're back in English. Meanwhile my Italian at work is improving faster than at home, which feels backwards.
Did learning with a native-speaker partner help you, or make it harder? Did you find a system that worked without turning your partner into a teacher?