Thumbnails still appear but the photo is gone - please help!

Question

I've already Googled the crap out of this, and it's happened before and I was able to use Finder to recover some of the original files, but I can't seem to do that this time. Maybe I'm not finding the link that helped me before or something but I NEED these photos.
I'm using iPhoto 11 and I use Lightroom 5 to edit. I drag flagged images from iPhoto to LR and then export to desktop first, then I move them into iPhoto and Finder - the same album in each location for easy access and multiple backup. I hear 'dragging' can sometimes mess with files, though I'm not sure why. And besides that I am not good at organizing LR so that may contribute to it. I simply import, edit, export and move onto the next project. I only want to use it like a post processing program, not an uploader or storage program....
When I test an image that isn't already gone like this, from the same album, it doesn't work. It won't drag and I can't even find iPhoto library while inside LR in order to manually upload it.
This must be an issue with LR/user error because the images that are currently gone are images I've already edited/exported. I'm sure to not delete from disk when I delete photos from LR though, so I just don't know!
Help I'm definitely lost here!

Answer 1

You start to go wrong right here:
I'm using iPhoto 11 and I use Lightroom 5 to edit.
Lr is not an editor. Like iPhoto it's a database with lossless processing. Images need to be imported and exported from it. You really need to choose between the two apps as they occupy the same role in the workflow. Using both is like writing your novel in TextEdit and Word at the same time.
I drag flagged images from iPhoto to LR
You're not getting your original files, just the iPhoto previews.
I only want to use it like a post processing program, not an uploader or storage program....
Then you are better off using a post processing program and not a manager instead of one. All your problems come down to that.
So, get an external editor - and in the list below they are all less epensive than Lr, - and your workflow will be a lot less complicated.
In order of price here are some suggestions:
Seashore (free)
The Gimp (free)
Graphic Coverter ($45 approx)
Acorn ($50 approx)
Pixelmator ($50 approx)
Photoshop Elements ($75 approx)
There are many, many other options. Search on MacUpdate or the App Store.
You can set Photoshop (or any image editor) as an external editor in iPhoto. (Preferences -> General -> Edit Photo: Choose from the Drop Down Menu.) This way, when you double click a pic to edit in iPhoto it will open automatically in Photoshop or your Image Editor, and when you save it it's sent back to iPhoto automatically. This is the only way that edits made in another application will be displayed in iPhoto.