Q: Seagate Not Working Anymore

I've being using a seagate usb ever since I got my Macbook Pro like 3 years ago. The last time I used it, it had that error message saying 'disk not ejected properly' when I was still using it and never even touched it. I've tried many things such as going into finder-preferences- and checking off 'connected servers' and 'external disks' but it still wont work. The light is on and I could feel it working it just wont show up on my Mac. Can someone please help me? Everything is on this thing!