https://metadata.nostr.com/ has a tool that helps you recover the lost data. It worked fine for me few months ago.

Or maybe just search around for "lost followers" for some more recent solution suggestions; it's quite common issue. 

 This is amazing! I see my old list, but is there a way to quickly just follow. 

 I believe there was something to just restore the previous version with few clicks. Dig around, you'll find it 💪 

 I found it thanks to @PABLOF7z! Thanks for the tip.