Having Stomach Bloating, Back Pain And Weight Gain. What Could Be This?

Question : I have severe stomach bloating & severe low back pain. The pain radiates down the buttock & down the leg & into the back of the knee of the one i just had Replacement done in July this year. My stomach feels really sickly & blown i have headaches through the eyelids right through the back I have a swelling right round my stomach through to the hips etc like a hula hoop & I was always flat tummy. I have gained a lot of weight which I never had. I also had a cervical smear as the doctor insisted that I had a cervix but i told her i didn't but she done the examination anyway & i when she inserted the speculum I felt a sharp pain & felt faint she stopped & said she would be back just to lie there for a while. she went next door to examine another patient & when she came back she said I could go now.I have had bloating since then ??? I wake up in the morning with chronic pain in my back & stomach until I just get up. very uncomfortable. I sometimes have to push to urinate otherwise it just stops until i push again then i pass some more until its all gone. I am a very fit person I take body fitness classes & Iexercise at the gym walk on treadmill for an hour but still gaining weight??? I hate this look also very tired after i have exercised feel like i'm fighting off falling asleep very tired could just crash

Just wondering if this could be coming from my necK. I was the victim in a car accident when the other vehicle started reversing on the motorway & then when parallell with our car turned, crossed 2 lanes & ended up sideways in front of my car. I was in the passengers seat & i yelled swerve to the right to avoid hitting her son in her passengers seat staring at me. My bottom came around in the seat I grabbed the handle above with my left arm which pulled my neck & shoulder badly & my knee went up under the dashboard causing severe injury later ending in a knee replacement. I have torn tendons in arm & remaining are delaminated. I'm trying to prevent surgery as I'm still recovering 3mths post opp now from knee replacement. Had so many cortisones for knee & shoulders etc as I fell & injured right shoulder sound like a cot case NOPE!! i still go to the gym & try to do cardio work cross trainer & exercycle bike & walk on treadmill. My neck is very sore though so i wonder could it all be coming from that radiating into my arms & down my spine & into my buttock & down leg etc??