More iCloud Storage Needed

I recently added 50GB space and uploaded all the photos to iCloud. Yesterday I sign-out and then signed in but now I can not turn on my iCloud photos option. Its giving me a message that I have to buy more space.

My photos are around 30GBs on iCloud.

and also one more thing. now in my iPhone some photos are also missing and on iCloud all photos are there.

Please help!