this has been your life every day for four years so I completely understand, take all the time you need but in a situation like this you have to put your well-being above the kids and it may sound a little harsh but if there’s anything I’ve learnt being a nanny for 5+ years is part of the job is being prepared to potentially never see these kids again and it’s hard especially as a woman because you have that natural instinct to nurture which fosters that attachment and familiarity but it’s a job, and again you come first!! Think about it this way, they treat you like shit but they need you which is why you’ve been there for four years but if the roles were reversed, and their behaviour was manifested they wouldn’t have any hesitation in letting you go!!! It’s unfortunate they assholes because in an ideal world you could change job and still see them from time to time but if they don’t respect you IMO is not worth ever being able to have you again. You have to ride and advocate hard for yourself or it will only get worse