Unable to clear all photos from iCloud

I am trying to delete all my photos from iCloud. It has 40,000 photos.

Option1.

I tried to delete from iPhone. Going into iCloud -> iCloud photos ->> Turn off & delete photos. It failed, says you own a shared Library. I dont see any shared Library on the phone.

I checked under settings-> Photos

Both images are attached.

Option2,

Tried from Web. Thats quite frustating, delete 1000 photos at a time. It will take me 40 attempts to delete 40k photos.

Also, deleting from recycling bin also takes 40 attempts.

(After contacting support over the case ID 1*************01, expert told me to delete 1000 photos at a time.

Someone help?

[Edited by Moderator]