Help!!! 😩😩 i don't know what to do .

I was dumb and in love and co-signed for a car at the age of 18 . My BF at the time and I ended up breaking up and once Robert told me he couldn't afford the car we purchased , I took it from him . My supervisor at the time reached out and helped me with two car notes . Well , I left for vacation last week and basically when I got back I told my supervisor I would be seeking other employment. I told her it wasn't official yet but when I did find something else , I would put in my professional two weeks notice . She got upset , had a fit and said that she didn't need a two weeks notice . So not only did I get fired , but now she won't give me my car back . I have been calling and texting and no response from either phones . Too many people are getting killed for innocent reasons so I refuse to go and try to get my car alone , but I don't know what else I'm supposed to do . How do I go about this kind of thing???