I have head pressure in the back of my head and every few minutes it feels as though a vessel in my nostril is expanding and contracting causing a mild but sharp and unpleasant pain in the back of my head. I have also had mild neck pain triggered by stressing the neck for example when sneezing and bending for the last few days. I suffer from hay fever. Last night I had a night of heavy drinking and did not sleep too much today. What could be the problem. I am 182 cm tall and 23 years old and weigh 73 kilos.