Talking and getting encouragement from someone else can be a great help in feeling better. Each person reacts differently to cancer therapy. Some people experience nausea, some do not. Also, symptoms can come and go throughout treatment. There are no medicines to get rid of nausea and sickness caused by chemo and radiation therapy.
Medicines are available to help, many that have no side effects.
Ask your doctor. Getting sick means the cancer treatment is working. Whether the treatment makes you sick or nauseous has no bearing on its effectiveness. Again, each person reacts differently to treatment. Some do not get ill at all.