Advice for leaning Japanese while working full time

I have very long working hours, most weeks I spend 50+ hours at work and often have to go in on the weekend as well. My work is 95% in English, so I don't get in any Japanese practise there (I am at a low intermediate level I would say, passed N3 in spring). I also feel bad whenever I try my low-level Japanese on my coworkers, as the conversation is always very slow and hard to follow. I really want to improve my Japanese, but on weekday evenings I am simply too tired to get a lot of studying time in, or have other important things to do like cooking meals, cleaning etc… I take a one-on-one language class once a week close to my house, where we mostly go over grammar concepts and I finally get some time to speak Japanese to someone. But obviously this is not enough. I am struggling to find ways to progress in the language… anyone have any advice?? I considered taking 2-ish weeks off work and taking some hardcore full-time class, but I couldn't find any short-term class like that at a language school, they either are 3+ months long or once or twice per week for 3 hours. I also considered in enrolling in more intensive evening classes, but having to commute to a school twice per week on top of my long work hours honestly doesn't sound like it will be feasible (and from previous experience I know that group-classes have been very unhelpful for me anyways). I am at a loss!! Any advice will be greatly appreciated

by MomoiroKakaricho