IPhone 4s iOS 8 most of my photos are missing

[iMore Question]

i had over 4000 photos ony iphone (shared with ICLOUD) and my phone had 0bytes free.
I suddenly noticed last week that the number of photos has decreased to 160!
They were not in the recently deleted album.
What could have caused it and can I recover them?
I logged into iCloud and can see done photos upto a month ago so maybe I can somehow copy those back but what about the photos from the last month which are nowhere?

 

[Just_Me_D]

"If" those photos were in your Photo Stream then they are probably gone, being that Photo Stream only stores the photos for 30 days.