Girlfriend threatening to file false case of cheating

I am in a relationship for 5 years and we knew that our parents won't agree so we decided not to go against them. We thought some day we will convince them and so we moved on. Recently we had a problem and she blocked me so I thought time will heal things and I decided not to talk immediately as it will boost the problem and I didn't try to reach her for 2 weeks now suddenly she comes and says that's I cheated on her as I did not turn back after the fight and she says Il not leave me and she Il lodge a complaint stating I cheated on her and she says she Il sue me and my family , her family has influence allover and from a middle class family please help me on how to proceed me my parents are not aware that she is gonna file a complaint , also please tell me Il that complaint affect my job as I am very much dependent on it please guide me further