Thanks for visiting the Apple Support Communities. From your post, I see that you are missing some photos from your iPhone after turning iCloud Photo Library off. I'm happy to help.
First, check your Recently Deleted album in Photos > Albums > Recently Deleted. If you see your missing pictures here, you can restore them back to the iPhone within 30 days of their inadvertent deletion.
If they do not appear in the Recently Deleted folder, hop onto www.icloud.com , signing in with the Apple ID you use for iCloud on your phone. Then, click Photos and see if your pictures are there. If they are, turning iCloud Photo Library back on, and select "Download and Keep Originals" from Settings > [your name] > iCloud > Photos or Settings > iCloud > Photos.