Language Absorption Pre-Medical School

Hello everyone! Not so quick question. My spouse and I, both 26 currently, lived in Okinawa for 3 years (2022-2025) and picked up the very minimal basics (Rōmaji only). We are currently looking at an opportunity to move back, but to mainland this time. I have my degree in project management, but it’s not what I want to do long term. I dream of becoming a doctor but obviously my current lack of fluency puts a major wrench into things. Upon researching, the Japanese government requires the highest level of language proficiency, N1, to be a licensed medical doctor. The jump from N2 to N1, allegedly, is its own feat in of itself since it introduces more intense vocabulary and dialogue. I would be tested on my language proficiency before I could even begin licensing exams. Before all of that, I would need to be generally fluent to even begin medical school in Japan. By year three, I must be able to speak, read, and write in all forms, introducing the need for N1 at this stage. A little background: My husband is fluent in both English and German. I only speak English. I have tried to learn German through him, but it never stuck. I don’t know if he’s just a bad teacher or I am incapable of learning another language. Maybe both. Maybe I wasn’t consistent enough. Maybe I wasn’t motivated because I didn’t ‘need’ to know German. Who knows. The point of all of this is to say, I am confident he will have no issues with this. I know Japanese and German are no where near similar, but he is insanely intelligent and can clearly learn other languages. So my question is, how long could it possibly take for me to get to the level I need? Everyone is different and I wouldn’t consider myself a sponge, but if you had to guess. Upon moving to Japan, my time would solely be focused on language classes and immersion, not casual learning and conversation. Has anyone who solely spoke English accomplished something of this nature? Not necessarily medical, but another career similar in complexity? Should this be posted in a different, more specific forum that I’m unaware of? I appreciate any feedback, advice, or answers from you all. I am open to any suggestions or questions as well. Thank you!