How do I delete my “deleted” pictures?

Do it in the Recently Deleted Folder.

Remove photos and videos from existing albums

1. In an album, tap a photo or video to view it in full screen.
2. Tap .
3. Remove the item from just the album or delete it from iCloud Photos on all your devices.

Delete or hide a photo

In Photos, tap a photo or video, then do either of the following:

• Delete: Tap  to delete a photo from your iPhone and other devices using the same iCloud Photos account; see Use iCloud Photos.
• Deleted photos and videos are kept in the Recently Deleted album for 30 days, where you can recover or permanently remove them from all devices.
• Hide: Tap , then tap Hide in the list of options.
• Hidden photos are moved to the Hidden album. You can’t view them anywhere else.