I am so sorry that CMM is having a difficult time of it right now. Hopefully the medication will ease the coughing and he won't have any side effects from it.

Could the iron deficiency anemia be a side effect of the chemo or any of the other medications that he is taking?

Sit quietly, the answers will reveal themselves when you least expect them to.
The past is gone, the present is a gift and you need to focus on today, allow the future to reveal itself when it is ready.