Missing iCloud photos on iPad air

Hello, I have a problem with my iPad Air photo gallery. I use one Apple ID account for my iPhone 6 and my iPad air. For three years i haven’t got any problems with both. But today i saw that all my ipad photos are gone (from iCloud too) and were replaced with my iPhone photo gallery. I have turned off all settings for photo sharing. I don’t know what to do, these photos are very important to me and should i restore my iPad? Thanks, Dilyana