This is a tricky problem and there are a few solutions, none of which are perfect. By far the best one if you can manage it is to delete your facebook account a

This is a tricky problem and there are a few solutions, none of which are perfect. By far the best one if you can manage it is to delete your facebook account and apps and never look back. Encourage whatsapp contacts to move to signal is probably just annoying for you and them but it seems to be steadily happening, so make sure you have a signal account.