I see what you mean. Somehow, the ability to delete one’s post is not possible, as you noticed. You can either ask me to do it (I have that ability as an admin) or you can edit your own post and replace it by “Deleted” or something like that. If you want to change the images or their order, when editing your post, you can just click on the X beside the individual images to remove them, and then, you can add another one.
Would that work?