i can’t find my pictures on icloud although i have backed them up long time ago. please help

You seem to be talking about two very different things:

• Photos stored in iCloud. Here would be the way to retrieve them. I do not think this pertains to your situation. iCloud: iCloud Photo Library overview
• iOS backup stored in iCloud. I suspect this is what you have done. This backup, however, would only contain photos from your Camera Roll, if you had one. Here is how to restore this backup. Restore your iPhone, iPad, or iPod touch from a backup - Apple Support

iCloud is not a backup service, it is a sync service. If you deleted them from your phone while it was connected to iCloud you deleted them from iCloud also. You should be able to recover them from your computer's backup, if you synced iCloud to your computer.