Mind games

Self talk goes something like this:
I am being treated for cancer.
The doctor said I would gain weight due to the high doses of prednisone.
ergo I can have that bowl of ice cream and that piece of chocolate, not just once, but every day. In effect Im making his prediction come true. 
How can I change this basic premise that I have been living under for three months.
The doc said I would gain weight. But that doesn't mean I should start eating ice cream every day.  Instead I will eat wholesome food as near as it came out of the ground or off the tree as possible. 
This morning I threw out a half gallon of ice cream and a box of Weight Watchers ice cream bars.
As long as it is in the house Im going to be thinking about when I can have some. I don't skip a day. The ice cream bar is 100 calories, and the ice cream is about 140 calories. Now that doesn't sound like much. But in a week, if I have it every day, I have added about 1600 calories, yikes!
I need to manage my environment. I need to not buy foods that are not right for me. If they are in the house, I will eat them. I need to fill my house with fresh fruits and veggies, easily available for snacking.
Im a poster child for every possible diet cliche that is out there.
So, here is my new viewpoint. Taking prednisone is not an excuse for eating poorly. I can eat, but not the bad stuff. If Im hungry I will eat the fresh fruits and veggies I have always available. I will make sure to match each snack with a protein source.