Drunk dizzy feeling, chronic headaches and cannot get my words out properly- what could this be?

I've recently been suffering from a few odd symptoms. I feel almost as if I'm drunk sometimes and I'm going to pass out. I have had some severe headaches that start behind my eye and go down into my neck. I've also noticed that when I "tell" my arm to do something it won't follow instructions. My legs feel weak and sometimes as if they aren't my own and when I try and explain myself my brain finds it difficult to almost put a sentence together. It makes me feel stupid but I'm worried about what this is and if it could be serious. I'm 19 from the UK normally fit and well. I suspected a mini stroke but I wondered if I was too young for this and could it happen without me realising at the time? Thank you in advance.