What Causes Pelvic Pain In Case Of Uterine Prolapse?

Hi there! Thank you for taking the time to read over my history..I am 41yrs old and started menstrating when I was 12 yrs old.. I was diagnosed With endometriosis 7 yrs ago after a laparoscopy/ hysteroscopy and D +C. I have had bladder problems and incontinence/ pelvic prolapse and ovarian cysts. 4 years ago it was recommended I have a hysterectomy Opted to wait and tried birth control for the hormones to help endo and did physical therapy for the pelvic floor problems.. About 3 yrs ago I started getting this pain that starts out like I have a full bladder and then works into a horrible pain with pelvic pain/ bloating/ pains that wrap around almost like contractions.. The pain makes it hard to stand up and i have to walk hunched over and can not wear pants around my waist.. Also if I sleep on my side or sit awkwardly It will bring on the pain.. Sometimes the pain will last just hours to days.. When I lay on my side I feel something sift inside. And then the pain starts. I have noticed that this pain occurs sometimes if I have had coffee or cola during they day. Also I occasionally have vaginal bleeding after a bowel movement ( my doctor has never addressed the issue just blows it off) my pelvic floor problems are: uterine prolapse, bladder prolapse, slight rectum prolapse and the urethra.. I have irregular periods.. VERY heavy flow and large clots sometimes as large as a small apple. The few months I almost think I am hemorrhaging !! I have had 2 trips to the ER due to the pelvic pain recently and all anyone (ER docs and my Gyn) will tell me is too have the hysterectomy sooner rather than later.. I would like to know for sure what is causing the pelvic pain before I have a hysterectomy. I do not want to have it and still have pelvic pain.. We recently did genetic counseling ( I have a family history or ovarian cancer) and I do Not have the BRCA 1&2 gene mutation. So I m still trying to decide whether to have ovaries removed during hysterectomy???? I realized I may not have outlined this very well.. And I m sure I will think of more to add later.. Any thoughts or advice you may have is greatly appreciated!!