I have used 111 GB out my 200 GB of icloud storage but my phone is saying my device is full, can’t all my photos be stored in icloud?

No, they are "synced" to iCloud and, using iCloud Photos, they are present on your device too.

And please, do not confuse iCloud with iPhone storage, as per this support article:--> What's the difference between device storage and iCloud storage? - Apple Support

Check both storages.

Regards

Giulio

If you’ve not already done so, you can significantly reduce the file size of the photos actually stored on your device by using “optimize”

Settings … Photos … Optimize

See: https://support.apple.com/en-us/HT205703