Have been feeling sick, dizzy, headache, eyes itchy. What could be happening?

Hi, for the past 2 days I've been feeling sick and dizzy. It all started when I was in college during my lesson. I broke out into a cold swear and my head started feeling all heavy. Then my head started banging and I started feeling sick. All day my eyes were itchy because of my lenses, I felt as if something was stuck in them so the discomfort lasted all day until I was able to go home and take them out. Anyway, I left college and slowly walked to the bus stop. I wasn't able to walk in a straight line and I felt as if I was about to pass out, my head was heavy. I come home and try and sleep it off but it's still the same. The sickness has gone but I still feel dizzy and my eyes hurt. During the time I was in college I was hydrated throughout the day, I had a breakfast and lunch at 12.00. I started feeling sick at about 3.20. Thank you.