Editor Crashes right after being started

I was making a game in Unity when I got a "stack overflow" error I think. I am not positive that it was a 'stack overflow' but I force closed Unity Editor with Task Manager. Now when I open Unity, it closes when it gives me an error message saying Unity is not responding and the only option I have is to "Close Program." Why is this?!?! PLEASE tell me this is not going to make my project accessible...

EDIT:
I closed Unity with Task Manager because literally 10 min after I clicked the 'Play' button when I was done editing a script, the editor just froze. My computer is REALLLLLLY slow so that could be why it was taking so long but I didn't expect this to happen.

 

Any suggestions?