Desperately Need Help To SAVE SD Card!!!?

After going on a trip to see my family, I was viewing the photos and videos from my SD Card on my my computer just fine. After sticking the card back into the camera to take another picture, I put the sd card back into my computer.

Now it won't read. It keeps telling me to "Format the Card". I don't want to do that because it will erase everything. Is there any solution to safely format or open the card on my computer without everything being erased? Those photos and videos are so precious and cannot be replaced.

Please help--I am so beside myself and almost devastated by this!!

Thank you.