What Causes Recurring Bacterial Infections Along With Pain During Intercourse?

Hi, I had a baby just over 6 months ago now and ever since I ve suffered with infections (bacterial and water infections). I ve taken around 8 lots if different antibiotics since giving birth. When being referred to the gynaecologist I had an examination performed and was told that my cervix was inflamed and given more antibiotics. Then I was sent for a kidney scan. The radiologist told me that the pipes leading to (or from [bad memory]) my kidneys were inflamed which were probably causing the infections. After that I was told by the doctors receptionist that it was all clear despite what the radiologist had said. The lower back pain that I am experiencing is awful and I ve always had pain when urinating within the last 6 months. My tummy feels uncomfortable but I m not sure if that s still things settling after the c section. I don t know what else to do as I feel as though the doctors are giving up on me. I must also mention that the pain radiates down my bum and thighs and have pain during sex. Can you suggest anything?