Bless your heart. I know that this is hard. just don't give up on finding your cure and remember that each one of us is so very different. What works for one may or may not work for another.
Your pain could possibly be elevated today because of the stress and being upset but it is good that your son is able to express himself. When my mom got cancer when I was 4, I didn't talk to her and shut everyone out when she returned from the hospital.

Is there anything you can do with him? How old is he?