Is it possible to reverse or revise ptosis surgery back to its original state? (photos)

The photograph you have included actually shows very symmetrical and appropriate height and curve of your upper eyelids. Of course, a comparison with your photographs prior to your surgery would help one understand what you mean by "flat eyelids."
Here are some basic bits of information that may help you moving forwards:
1. Whenever you trust to sign a consent form and have surgery with a surgeon, you should trust your surgeon to review your before and after appearances, usually physically but also with photographs so that your concerns can be reviewed and addressed. This is the best way forwards for you.
2. It is possible that you have mild lagophthalmos after bilateral ptosis surgery, which would explain the dryness in the morning. This can be assessed and addressed with an examination. Simple lubrication at night before going to bed may be all you need.
3. If your lids were to be lowered (this is possible), you may look like you have ptosis. So it is best to have the side-by-side examination of your before and after photographs.
4. In theory, upper eyelid curves can be changed if needed. However, dryness should be a concern and an examination will reveal that risk reasonably accurately.
Good luck