Hello Kryptdomi,
I believe a lot of the issues you mentioned here are related to adding/removing services without first checking how the service works. This lack of research seems to also have you missing the fact that deleted iCloud files, photos, and videos stay available for 30 days in the recently deleted folder and recently deleted photo album of iCloud. The photos are not permanently gone.
In your case they aren't likely to even be recently deleted. You can likely just sign back into iCloud, the photos will reappear, then you can download the originals back onto the iPhone if space allows.
When your selected 'disable & delete' you were being "asked if you want to keep a copy of the information that you store in iCloud on your device. Whatever you choose, your information will remain in iCloud." By selecting delete you told iCloud that you did not want the data copied to the iPhone after disabling iCloud.
This specifically sounds like you had enabled iCloud Photos. Since you were out of storage space on the iPhone it seems likely you would have also enabled "Optimize Storage" but neglected to enable "Download Originals" during the set up process.
Set up and use iCloud Photos - Apple Support
"If you need more device storage
iCloud Photos keeps all your photos and videos in their original, high-resolution version. To save storage space on your device, you can turn on Optimize Storage.
If you turn on Optimize Storage, iCloud Photos automatically manages the size of your library on your device. Your original photos and videos are stored in iCloud and space-saving versions are kept on your device. Your library is optimized only when you need space, starting with the photos and videos you access least. You can download the original photos and videos over Wi-Fi or cellular when you need them.
If you turn on Download Originals, iCloud Photos keeps your original, full-resolution photos and videos in iCloud and on your device."
You may need to turn back on the iCloud storage then download the photos manually. https://support.apple.com/en-us/HT204055. (You will have access until your next billing period)
If they are deleted this may help. If you're missing photos or videos in the Photos app - Apple Support
Lastly, you can provide feedback to Apple using their product feedback site. Here in the communities we are not Apple employees, just users helping users.
I hope this helps.