Advice for at uni for whenever you course starts.
when you get there, find out/register with the local NHS place, ask them about getting treatment for Social Anxiety Disorder.
Look for any local clubs or events for people who have it etc.
And take your time at uni, people will understand if you are slow to settle in the first few weeks. Try meeting your flat mates one on one first if that helps. just having one or two minutes conversations with each person should help you feel more comfortable when your all in a group.
Getting a job in a pub might help, i know of someone who had it, social anxiety, and it pretty much cured him working there.