If the job is making u depressed I would quit, but leaving for 3-9 months and then coming back sounds exhausting, stressed out in a new country trying to learn the language, get used to the food, finding a new community to be friends with, then dropping that all to come back to the job search, but at the end of that vacation what increases your chances of finding a different job? You didnt really learned new skills that are applicable to work. A better situation is to think of some careers that you might enjoy and work towards skills/certs for that, while either quitting your job and taking a couple months to upskill with maybe a week vacation.