Corrupted Dabatabase

 My database is corrupted, each time i try to list all the tables in the database  i have got the following message

I read that my best option is to use my backup. Before using my backup i would like to remove all databases in postgresql and create everything again from scratch. Unfortunatlly i can't see the list of databases, althought i am able to create databse

 can you suggest what to do? is it a good idea to reinstall postgresql?