Heavens...
Your GP is probably very good, but what he/she knows about Diabetes could struggle to fill the back of a postage stamp. As stated elsewhere, they are general practitioners, nothing more, nothing less. They will tell you things but YOU need to do YOUR homework and see what actually works for YOU.
I have a very good GP who knows little about Diabetes. The Practice Nurse is one who advocates cutting carbs down etc which is refreshing to hear. She is appalled at some of the advice Diabetic's are given. Both the GP and the PN have said that I know more about Diabetes than they do. Honesty.
My main clinical team are Hospital based and are an Endocrinologist and a DSN. Both absolutely wonderful and easy to talk to, as well as being very knowledgeable. Always know the latest information and willing to learn from the Patient's as well !
The Dietician I once saw is useless. I haven't seen her since, especially after I basically told her she didn't know what she was talking about. (Carbs do not make glucose - I kid you not)!!
As you said, "good job you found this site" Filled with Diabetic's, helping Diabetic's.