If sounds like you are having symptoms of depression. Symptoms for depression include fatigue, poor sleep, poor appetite, hopelessness, sadness, crying, lack of motivation, lack of interest and forgetfulness. When someone is sick from a chronic disease this can effect their ability to have stable mood. Because you are concerned about your health this can carry over into other things such as your mental health. Our mental health can be effected by such things as a concern for our well being. What you describe may be a situational depression where you are not born with a chemical imbalance but have depression because of a disease that scares you. Just as you are addressing your medical issues you should also address your mental health issues. A therapist can help you resolve your depression and give you support for the process that will get you well. Find a therapist in your area that would help you explore how to cope through your cancer. If you want to try medication you can consult a psychiatrist but he would have to know your other medications. I would try therapy first so that you have support and someone to talk to.
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