By Graeme Murray & Eleanor Ovens A teenager thought she was suffering from a hangover during girls’ holiday – but it turned out to be an incurable brain tumour. Ella Pick believed she was unable to keep up with her friends during a girls’ holiday to Zante because of a ‘hangover’. But doctors discovered the tumour. meaning she had just a year left to live. She felt ‘off’ towards the end of a week-long trip to the Greek island with four friends where she celebrated the end of college last June – but blamed it on her boozing and partying. But the 19-year-old, from Boston, Lincolnshire, began expe…