I simply wanted to comment and provide moral support. I know exactly how you're feeling at the moment. As everyone before me had stated, it's better to make this a learning experience and move on. You're on now dead (yet) and the 3.5 years of your photos were indeed a loss; however, you have the next decade or so that imagine the interesting images you're not only create, but take!

I understood the loss fully because like any other photographers, I had one of those "Oops!" moments and I lost a series of pictures I started in 2008. I thought I had backed up. I have my own schedule of 2nd and third backup. That moment came to pass and I was utterly angry at myself. The silverlining was that I had the RAW files to the TIFFs lost. The "punch in the stomach" feeling was that these new versions will NEVER be the same as the lost versions. They'll be similar and somewhat close, but not a complete pixel match of the colorizations and textures. I did print out some of those images out. The prints could give me some kind of direction to get myself in that headspace.