I hate my cancer doctor!?

I am twelve and I have cancer basically everywhere in my body. It started in my ovaries and then spread to my uterus and so on. It is now in my legs, lungs, kidney, heart, bladder, brain, etc. But that isn't the point. My doctor is kinda mean about the cancer. He cracks jokes that aren't funny at all (example: we checked on how the cancer is doing and my doctor said, "Wow, looks like the cancer is everywhere except for your toes.. *laughs*" This really annoyed me. And he acts like he doesn't care about what I am going through. I was recently told that I had until July to live. And he just laughs about it! What should I do about this? He is really bugging me and even the nurses think so; they give apologetic looks every time he cracks a joke. I don't know what to do about this and I need help about it so please answer!