I am an international student who's currently in a bureaucratic mess regarding my work permit application. I will get my permit possibly in February end. I completed my PhD thesis submission in December. Now, my PhD supervisor offered me a postdoc position soon after my defense, but I cannot officially sign a contract till I get my work permit. So, I don't have any official offer letter with me at the moment.
Should I be worried that I currently have no letter indicating the appointment and how can I handle the situation better?