Get a native anglophone partner and go live with them, force them and yourself to speak in English exclusively, especially when you argue or when you do errands

Get a native anglophone partner and go live with them, force them and yourself to speak in English exclusively, especially when you argue or when you do errands together. This forces you to simplify concepts to get your point straight at first, then pushes you to ampliate your vocabulary. Learned Portuguese in 1 year this way.