Photos in photo library gone

I wanted to manage my internal storage by moving some photos from my iPhone 6s to an USB through the computer. However, when I opened the map of my phone on the computer I couldn't see all of my photos, only a few of them. So I decided to manage them om my iCloud account on the website icloud.com. Therefore I thought the photos I deleted on this website would also be deleted from my phone. This was not the case so I wanted to synchronize my iCloud photo library with my iPhone 6s by turning it off and on again (found on the internet). However, by turning it off the majority of my photos were deleted from my iPhone because they were uploaded to iCloud. I can still see those photos on my iCloud account on iCloud.com but I want them back on my phone. I don't have a backup so I can't put it back on my iPhone by using a backup.

How can I get my photos back?