I’ve lost so many pictures just because my iCloud doesn’t backup , is any possibility of getting them back?

Photos don't generally just disappear.

1. Check iCloud.com/photos
2. Check your Recently Deleted album
3. Restore your photos from your backup (generally it's a good idea to have multiple backups of the most important data)

Do the photos show when you log into the iCloud website, and look for your photos there?

iCloud can be used for device backups. Do you have device backups using iCloud?

iCloud can also be used to sync photos. Do you have iCloud Photos enabled? (Photo sync is not a backup.)

If you look for your photos at the iCloud website and find them missing, check the deleted photos album and see if the photos are there.