I am sorry you are dealing with this. You are right to be concerned about undergoing surgery. For one, there are always risks with any surgery and, secondly, many women lose an ovary or ovaries for ovarian cysts when all that should be removed is the cyst itself. Removal of any part of the "reproductive" system has been shown to cause permanent harm since the uterus, ovaries and tubes have lifelong functions.
Most cysts resolve on their own, no intervention needed. Multiple simple cysts can look like a cyst with septations hence a complex cyst. So it is possible the cyst in July was a cluster of simple cysts. It would seem possible too that this has not been the same cyst(s) but different ones developing as cysts are a normal part of the menstrual cycle. And surprisingly, menopausal women can also develop cysts that do not need intervention.
Typically, they don't do surgery for such a small cyst since most resolve on their own and imaging is not exact so what may appear complex may not be. This site has some good info - http://ovaryresearch.com/ovarian_cysts.htm. This site - http://www.overy.org/ - addresses removal of both ovaries. However, studies have shown removal of even one ovary causes harm such as a significant increased risk for dementia and parkinsonism. It can also cause an earlier menopause which ups your risk for a number of other health problems. And fertility is usually impaired.
What did your gynecologist explain as the reasons for wanting to do surgery for this small cyst? Ovarian cancer is rare with a woman's lifetime risk being only 1.3% (less than 2 per 100 women will get it).
My gynecologist whom I had trusted for 20 years used ovarian cancer scare tactics to get me to consent to what ended up being gross over-treatment. My cyst was 9.5cm at the time of surgery and probably did need surgical removal. But he was deceptive in a number of ways to get my consent for organ removal that was unwarranted. I have been suffering all the negative effects ever since. My surgery was 12 years ago.