Wow. This is a tough question! I used to do reviews for insurance companies and I would probably have this case reviewed by our medical panel. Some insurance companies are very strict and if you don't actually have cancer would not cover it. I do know that the company I used to work for needed the oncologist to state the patient had cancer in order to be approved. It really can't hurt to put in a request for it. Most insurance companies require prior authorization for IVF. The worst thing that can say is no and you will still have the right to appeal the decision and have it reviewed by a medical director that is an oncologist.
I'm not sure if there is other funding out there but again, there is no harm in asking around.
Good luck on your journey.