"Concerned by delay in my diagnosis"

about a month ago I had terrible side back pain and I went to A&E. after having various tests and waiting 5 hours, I was admitted to obs ward were my pain increased so much that I ended up having to be given morphine and oxygen. during the day and after seeing a couple of doctors they were diagnosing that I may have kidney stones or stones in the pancreas. I was then transferred to ward 1, surgical ward, where I was put on a drip and also oxygen to help me breathe. after seeing a couple more doctors, I was told that they were not sure what I may have and I then had to have x-ray blood tests and given heparin injection into my tummy. after a few days the pain decreased and I was moved to ward 18. on that morning, I was seen by a professor and some students, who informed me that I had pneumonia but that I could be treated at home, so I was discharged on that day and given 4 days supply of antibiotics. after a couple of days at home, I was not feeling any better and also received a phone call from the hospital telling me that the ct scan I had had whilst in hospital was causing the specialists cause to concern and that I should return to hospital immediately. I returned to hospital and was admitted onto obs ward. the next day I saw the chest specialist, who told me that I had a possible shadow on my lung and that I had a pulmonary embolism. I was moved to ward 23 and put on heparin injection and that I needed to have an examination of my throat and chest. happily the test I had was clear but my embolism needed to be brought under control, to help this, I was put on Warfarin daily and I was in hospital for 9 nights. I now find myself having to return to the hospital every two days to get my INR checked, because Walton clinic cant fit me in for three weeks after leaving hospital. I will be on Warfarin for the next 6 months and hopefully I wont have any other clots this year. my care at the hospital was first class and I have nothing but admiration for the way the nurses cope with their heavy workload and shortages of staff. however, I am disappointed that after seeing so many different doctors, I received differing diagnosis. surely I should never have been discharged with the symptoms I had and I wonder that my CT scan was not checked properly.