Hi Marjorie and welcome!

I understand how you feel about having to go on meds after years of diet control. I found myself in the same situation a few years ago. With low carbing, I did manage to get back off the meds again after a few months of low carbing.
As for the Glucotrol; I think it would probably be okay for short-term use but if you find that you will need to stay on it long-term, I personally would request to be switched to something that was not a sulfonylurea such as Glucophage (Metformin) simply because of concerns with pancreatic burnout.
I hope that the Holter monitor tests came out alright and if they showed no problems there, you might want to talk to your doctor again about stopping the Avandia and finding something else. IMHO, medicine shouldn't make you feel worse and if it does, something else needs to be tried.
Let us know how you're doing!