This is why you back up your pictures. If you lost your phone the same thing would have happened. What you need to do from now on is have a folder in your media pictures called "new pictures" That way you can remember which ones you haven't backed up yet. And then have your camera auto save them in the new pictures files. And the stuff you save online or from mms save it to new pictures. Every week back them up on your computer and put them in whatever folder you want.
Then after they are already on your computer and backed up move them from "new pictures" to each folder you want like, "me" "animals" "places" etc. This is what helps me. Because if you take a new picture of yourself and put it in the "me" folder but you already have 100 photos of you then you won't know which ones you put on the computer already.
I also do this with files. I use the same method when saving files on my computer. They go into "new files" and "new pictures" until they go on my external hard drive. And then they go in the folder of the category they are in.
Let this be a lesson learned for you. Always use that SD Card and be worry free. I still have pictures on my SD card from a phone I had almost 5 years ago and its great. Also do a PC Backup incase your card dies.