Unity Keeps Destroying My Projects. Please help! (Urgent)

I'm going to keep this short.

The other day, our first alpha build was completed. We released it to the public and everything went great. Apart from the fact that the next day I went to open it up and it said that it couldn't open the scene because it's file version was higher than what Unity supports (despite the fact that I have the latest version). I tried multiple fixes and just decided to rebuild it since I hadn't lost any files, just the scenes. I managed to rebuild it all in about 2 days, finishing last night. I was pleased and everything was working great last night. I shut down my PC, no crashes or anything, and went to bed. I opened it up this morning and every time I try to open the project it crashes and I get a bug report screen.

Quite frankly, this is ridiculous. I've never had any problems with Unity but this is something which is literally stopping work dead in it's tracks. Our team is up for release on Steam next month and we just have too much to do to be losing time to stupid errors like this.