How to repair corrupted PostgreSQL pg_toast error
I'm sorry you ran into that kind of problem, due to device failure. I suppose you don't have any backup (either physical or logical) from before the corruption.

You may find interesting things in Christophe Petus's conf talk "Corruption war stories". You'll find the slides here and the youtube video there.

What you could do is trying to copy all your uncorrupted data in another table (created with create table like for example to preserve constraints, comments and indexes), drop the other table and rename the new one...