Seems like you messed with CNAME file.

None of your branch has that file which is created by Github. Do not delete that file.

Try setting domain name again.

I have also noticed from https://github.com/sdabhi23/sdabhi23.github.io/compare/master that when you set the domain name you selected "shreydabhi.co" not ".com".

Make sure you use correct domain name too and wait 24 hours after the update.