Cancer throws raw many emotions: Anger, grief, fear... It may help us to talk to professional counselors to have some strategies to cope with it all.
I had a brief rough time during my second cancer treatment when due to a small incident, I was reluctant and wary of resuming treatment. My family suggested that I speak to a counselor. I was reluctant at first. However I met the counselor and I am glad I did. It helped me in several ways --- first, a way to pour out a lot of what I was feeling, learning a few tricks to help cope with the anxiety I felt, and third she tagged me as being "resilient", which I really loved :)
Please do due dilligence before approaching any of the folks recommended by each other.