What Causes Depression While On Femara For Breast Cancer?

I have stage 1 breast cancer, non invasive of lymph nodes, had surgery to remove cells, followed by radiation. Now on Femara for about a month. I am 78 years old but been very active, ballroom dancing and competitions. I seem to have a sense of desperation, maybe just depression. I can t decide if it is just a normal reaction to all I have been through or the Femara that I have been taking. Lost interest in dancing and really uncomfortable around other people. Will see my doctor in about a week, do you advise trying another form of the pill I am taking?