Thank you for the question.
It sounds like you may need to do some more research into your specific situation. You may want to start with a consultation with a well experienced board-certified plastic surgeon and a conversation with your insurance company.
The plastic surgeon will be able to inform you if you are a good candidate for breast reduction surgery and submit paperwork to the insurance company on your behalf. Your communication with the insurance company will provide you with information about your policy and "coverage" of the breast reduction procedure. You will be able to ask specific questions in regards to your “share of costs” (if any).
I think once you have done these two things you will have most of your questions answered precisely.
I would suggest that you remain persistent; breast reduction surgery is generally one of the most patient pleasing operations performed.