I think that the MacAir 13" has an SSD, so if someone is willing to sell you "data recovery software" for it, run the other way.
Most people don't do a repair unless they think something is wrong to begin with, so it's hard for us to know what's going on. More than likely the pictures are OK and you just can't find them.
One possibility is that when you are running Photos, you're looking at a different Library than you think. You can see if you have more than one Photos Library close Photos, option click the Photos icon, and open the Library Chooser dialog:

As you can see, I have several Photos Libraries. If you find that you have more than one, use this to choose other ones and see if you find your pictures.
If you can give us more information about what caused this, it will help. There may be other possibilities. Let us know what happens…