My Mac is being stupid?

So I have a Nikon and I take pictures all the time for Weddings and Seniors. I just plug in my memory card and my Mac reads it no problem, usually. I just put it in after looking at the pictures on my camera and they wouldn't show up on my computer. I took out the memory card safely and put it back in my camera and the pictures up until the ones I took today are fine but the rest are just completely gone. I don't know what happened and I'm freaking out. This was a paid senior gig and the pictures just freakin disappeared. What do I do? Did my computer eat them? I'm so scared!/

Your Mac is not stupid. The disc is stupid. Use recovery software to get back your photos.

After you recover as many photos as possible, use the camera to format the disk. All data will be removed. That will correct the faulty file system.