Hi Norma,
Byetta isn't an instant cure, it takes time and the higher dose should certainly help you. What other meds are you on?
In my case the weight started to reduce very well, but the blood sugars weren't responding. My consultant added Amaryl (a sulphonylurea that encourages the pancreas to produce insulin) - initially 4mg, then 2, then 1 and now down to 0.5mg. In a month or so I hope to be able to drop it completely so will then be on just metformin and byetta.
I also found for myself that my diet had too much carbohydrate, so have halved the carbs and increased the protein. That made the biggest difference to my BGs. When I started on Byetta my HBA1C was 8.6, then 8.4, then 8.3, currently 7.9. I am due another in a few weeks which I am confident will be below 7.5.