Hmmm, sounds uncomfortable! The lower extremities (gyn, digestive, lower back) can often be VERY interconnected.
For about 5-10 years I had periodic pain that was terrible--abdominal bloating, severe cramping, burping, lower back pain, slow bowels. It would usually pass within 6-8 hours. We went down the digestive path, thinking it was connected to that, but nothing particular was found. We went down the chiropractic path, which helped for the back, but arch inserts ultimately helped work preemptively with that and I rarely need a chiropractic adjustment any more. I've also had a history of ovarian cysts.
Then about a year ago, I had a particularly severe case that put me in the hospital because a fever was also included. It turns out it was an abscess of my fallopian tube and ovary. Who knows if this was it all along, and it finally just got really bad. But it explained many of my symptoms.
When you are having gyn issues (cysts, abscess, etc.), it can slow down your digestive system. Slower digestive system can cause digestive upsets and back issues. The stress of all of those can cause headaches. All of the above was disruptive to sleep, leading to forgetfulness and tiredness. Amidst all of this, my thyroid levels started to go off, further contributing to tiredness, forgetfulness, and my hair even began falling out. After my hospital stays, at least the thyroid corrected itself.
For you, it sounds like the digestive and gyn issues are all wrapped up together to complicate things. Lots of fluids and cranberry juice can help flush your system. Lots of yogurt can help build up healthy flora in your digestive system, especially after a bout with e coli. Careful tracking of your periods, and/or changing off of the Depo shots, may lend some answers to your gyn questions. But trust your gut. If it hurts, something is not right. Your body is not supposed to hurt on a regular basis.
I began to feel like I was a hypochondriac because nothing was ever found. But I ended up in the hospital finally, lost the right ovary and tube that was severely abscessed. And six months later, the left side became abscessed as well. I didn't lose any parts on the left side but ended up with a three-day hospital stay and two weeks of home IV antibiotics, followed by three more weeks of oral antibiotics. But a whole host of my problems now seem to be solved.
I think my right ovary has been problematic for decades and we just could never peg anything specific on it. Personally, I'm glad to be rid of it. We were never able to have a second child anyway, so be gone!
This may not be your situation at all, but please be aware of how interconnected our body regions can be.
My husband was frustrated to have one doctor question whether we were a monogamous relationship--often the cause of some gyn issues. We had a couple of good discussions and arguments over that one. But we realized we each were saying to ourselves, "I know I'VE been faithful, what about you?" This whole mess has brought us much closer together. Nothing like a long-time health issue being resolved! It takes a toll on a relationship, even when both have been faithful, when one is always feeling awful physically.
So, good luck and be persistent. It's your body and hopefully you will find some answers some day.
P.S. I'm no doctor, but my gut says a lot of your issues are related hormonally. I'm nearing 50 and my brain is useless as I near menopause. (My mom said she lost her brain from 45 to 50, then she went on to get her masters and doctorate.) But my best friend from childhood was in the throes of menopause in her early 30s, after many challenging years with endometriosis. So, who knows? Anything is possible when it comes to women and hormones.
Good luck!