I have been dealing with cysts for two years now. Even a small cyst can cause a great deal of pain, especially if it ruptures. Then, again, sometimes cysts, even larger ones, don't cause any pain and are not discovered. Have you tried different brands of bc pills? One brand may give you a migraine, while another brand may not. You also could experience side effects from the pill for the first 3 months, while your body is adjusting to it, and then not have any side effects after your body has adjusted. If you are in that much pain from a cyst, you should talk to your gyn about it. He or she can prescribe pain medicine or they may change their mind about surgery or come up with alternate treatment if they know that you are in that much pain.
Best of luck to you! :)