"Urgent Rheumatology appointment waiting times."

5 weeks ago I was struck down with an unexplained illness, unable to work or function properly and after many visits to the GP and the walk in centre in the early hours of the night I am still waiting for an urgent Rheumatology referral appointment. I was told by appointments bookings that the wait is 6 to 8 weeks for urgent referral's and 18 weeks for non urgent. I am shocked of the prospect of waiting that long and not being able to work. I am wondering why there is such a long waiting list and if all NHS hospitals are the same.