Have you ever been diagnosed with endometriosis? Your symptoms sound similar to mine, although I was much older when diagnosed with my complex cyst. My cyst was described as complex and had solid components but it was simply an endometrioma that had damaged the ovary so badly that it was stretched out of shape. It appeared enlarged on the ultrasound it was stretched so, and half-enclosed by the endometrioma.
Some cysts can be removed from the ovary and the ovary will resume normal functions as soon as it heals. Other cysts can be removed, but cyst will have damaged the ovary, or the surgery will damage the ovary, preventing the normal function. At any rate, it is my understanding that losing one ovary only decreases the chance of conceiving a child by about 20%. And I know women who have lost ovaries for a variety of reasons who later had children without even the need for infertility treatments. Likewise, there is a member of my famiy who lost and ovary, and had a cyst removed from her remaining ovary, who conceived a child, again with no assistance (other than the participation of her husband!!)
Be certain to let the doctor know of your desire for children, so that the procedure can be done with that goal in mind. It might still happen that nothing can be done to help the ovary, but a specialist will be your best bet in the surgical ward. AND, if there is any reason for the doctors to suspect that the cyst might be cancerous, then our advice is to find a gyn oncologist who specializes in cancer detection and removal.