I need to see a doctor ASAP but I'm not registered, what do I do?

I am not registered to a surgery because I went to university and registered there but could only stay at that surgery for my first year (makes no sense I know) and when I tried calling to retrieve my details they were beyond rude, now I am staying with friends in a different area for the summer and need to see a doctor ASAP I've read everywhere that you have to have proof of address but I don't have post delivered there, unis too far to bother with that again and home won't take me because I left their surgery. I just want to see a doctor why is this so hard. Is there anywhere I can go to get checked out where I don't have to piss around with registering in the Milton Keynes area???