Good Luck Gaz with whatever you do. I remember absolutely sh!tting myself when I was leaving school, but it all works out. Try not to panic. Thing is, it's not like you only get one chance to pick a career nowadays. People in their 40s are going back to Uni and doing stuff they never dreamed of doing before. So, it's not like you have to get it exactly right first time! Just make your choices and take it from there.
You will be fine mate! I have faith in you!