Last night I got aulted?

Last night I was walking my friend home to her boyfriends and a gang of guys and girls started on me, there were at least 11 and the next minute they punched me and started kicking me in the head repeatedly.Eventually a few witnessed dragged them off but I was sent to hospital. Now I can't sleep. My head is injured and I am too scared to sleep, every time I close my eyes I see them. What can I do other than see a councillor and has anyone had a similar problem before. Thank you so much xxx