Hey Bonnie, and
Your doctor has the right idea about not "dieting". The problem with a diet is that it is temporary...you go "on" a diet, then you go "off" a diet and return to your old habits, thus regaining all the weight you'd lost. I prefer the term "lifestyle" changes. You can't "mess up" a lifestyle, nor can you go off of it. You can improve it, tweak it, whatever...but you can't "fail" at it. You just keep trying. So congratulations on your healthy attitude.
Stick around. You can do this!