Just wanted to chime in. Since this cyst is still on the small side, it may very well resolve on its own. You don't want to have surgery unnecessarily. I believe around 7cm is the "cut-off" for monitoring a cyst versus surgically removing it provided there is no or little concern of malignancy (VERY FEW cysts are cancerous). It is not unusual for the ovaries to develop cysts after hysterectomy because the loss of the uterus can impair ovarian function.
The MRI and CT reports should have some details about the cysts' characteristics. That can be helpful in understanding the type of cyst and its chances of resolving versus needing surgical intervention. So if you don't have those reports, you may want to get a copy.
Let us know what more you find out once you get insurance coverage.
I had a very large (11 cm, grew to 14 cm) cyst two years ago. I was also in a lot of pain, because of my pain and the size, I was referred to a GYN. I was able to work with the hospital and the GYN to make financial arrangements and got a charity deduction prior to the surgery. I suggest you contact the Dr. office and hospital to explain your situation and see if they will help you. You may also try going to a public health clinic.
Sometimes cysts will resolve themselves, but other times they do not and need to be removed. Since you no longer have periods, the cyst could be complex and complex cysts often need to be surgically removed. Try not to worry too much about cancer...although I know from experience that this is easier said than done! The majority of cysts are not cancer and cysts are quite common. However, if you are past menopause, the risk does go up and cysts post menopause are typically taken more seriously. While, I wouldn't get too worried, at this point, I would probably not wait until the insurance to be seen by a doctor.
Hope this helps some. Keep us posted!