What Causes Fibrioctic Cyst?

I am 34 I weigh 112.lbs and have 2 boys and miscarried his twin girl at 5 months pregnancy..My youngest is 9 yrs old now and I:ve had the lining of my uterus burnt 2 times now and as I get older things are getting worse..I collasped the other day on the step with the pain and was taken by ambulance to find out that I have fibrioctic cyst but not sure yet how bad ...waiting to be refered to a specialist for further info... been like this for 8 yrs.. if I lift, push,pull, I pass black stuff... can you help me?