How To Lower Cholesterol Level, Sugar Level And Thyroid Level?

Hi I am a 52 year old female. I just got a blood test back that said my thyroid level is 5.5, my cholesterol is 244 and my sugar is 108. I am on synthroid 25 mcg per day. I gained 10 pounds in the last three months. My doctor wants me to start cholesterol medicine. But I would rather do it my self with diet and exercise. I am pretty energetic and always moving. Is it smart to do it this way or should I opt for pills?