What Causes Increase In Blood Sugar Levels Even After Losing Weight?

Hi there, I m 43 years old and last spring my blood glucose was considered pre-diabetes for the first time, at 115 range and 3 months later same thing i was re-tested and same thing. 2 months after that I had a total hysterectomy and had already started losing weight, when I went back for a 2 month post-op check and was diagnosed with type 2 diabetes-- My blood glucose number was at 276. Why now that i ve lost another 15 pounds (down to 215 lbs at 5 7 tall) does this seem to be getting worse, rather than better for me? The common denominator in all this seem to be my total hysterectomy. I chose not to take anything for the hot flashes that started and now think this may have alot to do with my crazy blood work results. Any ideas or clues? The Metformin seems to help, but now my vision and other symptoms have begun that I never used to have and i m still losing weight! I m down to 204 lbs and it does not seem to help! Any idea why this, NOW that I ve lost weight?? (I ve lost 20 lbs since my hysterectomy and had already lost 15 when diagnosed with pre-diabetes the first time). Thank you so much!!!