Severe lower an pain with feeling of semi paralysis in lower body

I'm 32 and have been with my boyfriend for 10 years. This has happened to me many times in the last decade. I was monogamous up until a couple of years ago. My boyfriend is between 6-7" and not that thick. Other men I have been with are much larger and thicker and one would think that the larger penis would cause this pain but its actually the other way around. It's happened a few times when riding my boyfriend and I bend my upper body back in order for his penis to hit my g spot. As soon as he cums and I unmount him, and begin to get off bed and walk to bathroom this terrible bloating and severely intense pain hits the walls of my vagina then shoots right to my lower abdomen. It's gotten so bad I've ended up in ER or Urgent Care more than a handful of times. There's been maybe 3-4 instances when I literally have not been able to take full breaths, let alone walk. The last time this happened, prior to incident from two nights ago, nonintercourse was involved. I was simply having dinner and as I got up thinking I had to pee, the pain got me. I sat on toilet and attempted to urinate but instead found myself unable to move any part of my body. I was sitting with head kind of crouched over my legs and basically remained in that same position for several hours. I cried for me boyfriend to come help me but couldn't even let him in through bathroom door since my legs were blocking it from opening. I had to inch ( and I really do mean "inch") my legs (unable to pick them up off floor) until he was able to finally squeeze in through door. When he made it in to bathroom poor guy had to deal with my loud crying and inability to move any part of my body below my ribcage. I was forced to hurdle over still in same crouched position all the way to our car so he could drive me to ER. While at kaiser I was given morphine three separate times in order to ease the pain. Now this used to happen maybe once ever couple of years up until last year. Now I'm experiencing this same pain on average once every two to three months. CT Scan, blood work, many Pap smears, multiple ultrasounds both vaginal and over belly have come back normal. I'm growing tired and concerned this will never go away.