As someone who has had PCOS symptoms all her life but didn't know what it was until it resulted in the removal of a huge ovarian cyst and hysterectomy, I can give you this advice:
If she is bleeding heavily during her periods she is probably also severely anemic. This is one of the symptoms that can be treated that will give her immediate results. She will regain some strength that will allow her the energy and desire to work on getting better. Taking iron supplements and eating iron rich foods may not be enough if it is severe anemia. In my case, it took a transfusion of 3 pints of blood. The cysts rob her body of nutrients so she needs to be religious about taking daily vitamin and mineral supplements.
If the PCOS is serious enough, she does have the option of having her ovaries removed while keeping some of her eggs frozen for future use and having them implanted in a surrogate for future pregnancies. It may even be possible (I don't know) for her to keep her uterus and have the eggs implanted in herself (don't know if a healthy pregnancy is possible without ovaries).
If she is on birth control pills and still experiencing many of the PCOS symptoms then they are not working for her and her doctors need to move on to other alternatives. She may need your help with being more assertive about this with them if she's low on energy needed to fight for herself.
It is just as frustrating for her as it is for you, especially if she is experiencing weakness in her body and losing energy and stamina to do the things she wants to be able to do with you. Sometimes it might take more than an equal sharing of the chores to enable her to store up enough energy reserves to share some of them with you. For more on this, I urge you to read this short story called
The Spoon Theory. It is one of the best ways I know of to help someone understand what an energy-zapping illness does to a person so they can learn how best to help.
One of the more frustrating experiences I had with it was a feeling of helplessness and an inability to get people to understand what I was going through so they could help me help myself.