I had deleted my pictures on my phone thinking that was backup on my iCloud however it is not on my iCloud. Is there anyway I can retrieve all my pictures back?

Check the Recently Deleted file. The only other hope is that you backed them up to your computer or another device. As you have discovered, iCloud is a perilous place to store photos and other important data. It is so easy to delete them unintentionally. I always suggest that important things should be stored on your computer or an external drive.