Oh Scarlett - you poor thing! You will get support on here. Where are you situated?
Firstly you need to find a good counsellor to help you work your way through this. Especially if your mum isn't being supportive. Secondly, if you feel you need a second opinion - go get one! You need to find a good doctor that will explain everything to you, give you your options and help get definitive answers. This is your right. Quite a few women on here suffer from PCOS so I am sure that they will rally to give you more specific advice regarding this condition.
Depression is so debilitating but help is out there. There are many groups like Beyond Blue that can help. You have your whole life ahead of you. Please keep posting how you are feeling on here so we can support you.