Hi Belinda
to take your points singly:
yes you can improve levels by diet and exercise. Diet in particular. Reduce your carbs drastically and the levels WILL come down. Metformin is a good medicine and might help a little with weight.Low carb is good for that too.
High carb diets
Are advised because of a misundersanding sparked by Dr. Ancel Keys in the USA. He believed that fats caused elevated cholesterol and that resulted in cardiovascular events. He had no evidence for that, it was pure assumption. He wasn't a medic, but a Ph.D!
He was wrong, but "shouted" so loudly that his beliefs became facts( from the very beginning, there were doctors who opposed his views and were shouted down)
Many medics, who follow what they were taught,blindly, truly believe that carbs are essential THEY ARE NOT and that if you reduce your carbs, you will make up for it by increasing your fat intake, which will lead to CVA. IT WILL NOT
Read through these foums and find out more about this stuff. them bake yourself a Fergus loaf and spread it liberally with butter and top it with cheese and ENJOY without guilt.