Ah, thank you for the reply! This makes sense now, my mum also said the same thing but I didn't really believe her...it was really scary though!
Thank you once again Caryopteris :)
Startling as this is, it is a phenomenon that can occur from a cold virus. I have had it happen about 3 times in my life, and have heard other people get it at about the same rate. Usually you have a scratchy throat or other upper respiratory infection symptoms, but they are not very dramatic, so when suddeenly this fluid that seems thinner than water gushes with no notice, it feels like your brain is leaking spinal fluid out your nose. Fortunately that is a rarer cause of fluid gushing from the nose!