I m having a problem and thought u people cud help-

so,recently i inserted a new pen drive in my mac and @ 1st it showed up in desktop ,disk utilitiesand finder! But then i went for bakup in TM and i accidently erased sumthing!! Nd now it dosnt show up in findr,i cannot evn partion it ! 😟 So wat can b done?? Help needed plz 🙂