Do I understand you correctly, and you did not only disable iCloud Photos on your iPhone, but used "disable and delete" to erase the photos from iCloud as well? Then try to get help from Apple Support. Perhaps they are able to recover your photos from their backup.
There is no other way, unless you have a backup of your iPhone or iPad on a computer. Then you could recover at least some of your photos by restoring the iPhone from that backup. As you have been using Photos, when you deleted the photos, the iCloud device backups will not contain your photos. You need a backup made on a computer, for example with iTunes. See: How to back up an iPhone, iPad, iPod Touch be able to Recover Accidentally, Permanently Deleted Photos - Apple Community