How to help a sick person out of fear of being sick?

Dear Friends..

Today I am going to share my personal experience. My mother recently had to do blood test, which was her first experience of doing it. Firstly, she was too scared and upset that she had to go through this. Secondly, she was very adamant to not get a check up done ( I have been behind her to get a test done since a year, so here you all can imagine how rigid she had been.) But some how I managed to get it done and was very shocked and depressed that she is being diagnosed by diabetes and Thyroid disease. This really scared me at first ( which made me cry and disturbed my mind all the time ). I wanted to be with her so that she doesnt go into depression. But she still doesnt expressess her pains, her feeling, her frustration with life and this is what makes me angry, upset, and what not. Its been a month and I have noticed that she is going through mood swings, irritability, depression. And I am helpless as she is in no mood to listen to anyone or talk to anyone. I am doing my best to ensure that she follows proper diet and have her medicine but still I am failing to get her out of it. She is so scared that the moment i take the name of diabetes she says not to mention it. What To Do????