Thanks for all the replies, I'll look into seeing my doctor - it's just a bit awkward because I'm going home for Easter in two weeks, so I'd have to wait for any uni services anyway. It's an on-campus surgery, so I assume they can signpost me to whatever the university has available? I can always visit my doctor back home if it gets worse during the holidays, but unless they wanted to give me medication (which I know doesn't work immediately anyway) I'd probably be told to wait it out and see someone at uni.
When I finally got to sleep last night it didn't last - I was waking up every hour with a ball of anxiety in my stomach. I will try the herbal tea idea, thank you.