I had a full hysterectomy, executed by laparotomy 11 months ago and I am still swollen and in pain, Why?

I will try and keep this as brief and concise as I can so please bare with me. At the age of 59 I was diagnosed with cancer of the womb the doctors decided that the best course of action given my age was a full hysterectomy performed via laparotomy (keyhole). As far as the caner is concerned the operation was a complete success and all subsequent scans have been void of caner, hurray. My problem is concerning an undesignated ramification or side effect of the operation. For eleven months now I have had swelling in my lower abdomen which is hard to the touch and very painful. The best way to describe the pain is to compare it to being heavily pregnant; there is a constant pressure (painful) forcing down on my pubic bone. I have been to many doctors to no avail, I have had an colonoscopy, X-ray and CT scan and apart from diverticulitis I was told that everything was clear. What I am hoping for is that somebody here has experienced the same thing but through the wonders of medical science has seen it through. Please any help or advice would be greatly appreciated as I fell I have run out of options as my doctors think that we have explored all avenues.

One last thing; I do take my age into account when considering my problem (as the doctors keep reminding me to do) but after eleven months regardless of age I find it hard to believe that I could and should be periodically bedridden due of pain.

Thanks you.