congratulation's we have had lots of people accidentally upgrade firmware, I think you are the 1st to accidentally delete cydia! 😱 so a little info device type formware version an how did you jailbreak it.
Plantbeing does not recommend rerunning the Absinthe jailbreak over the previous jailbreak. I'm not sure if that would work you can try. worse case you have to reinstall stock software then rejailbreak. what do you mean it's hiding what about if you search for it in finder. how did you accidentally do this since it's not easy to remove cydia normally it's done with Cydelete in cydia.