What they should have told you is who your Admin contact is for you University's HigherEd license, so they can start a support ticket for you.
Dear Esri Support,
Please don't do this to students. #MinimalEffort
Esri told me that they couldn't help and I just had to ask my uni, so I asked my uni support guy and he said he didn't know how to get it back so I just have to start again. I've basically rewritten my references now but it's just annoying because I think I've left a few things out and can't remember where I got them from as I've been doing this project for the last 12 weeks.