I know from experience that although I managed with diet and exercise control , for 4 years , the diet I eat initially and weight loss I achieved were not sustainable for me.
Now 12 years in and on 3 different medications, for the last 2, I reduced my portions , reduced my carbohydrate, intake. My weight is more stable and has slowly come down. My HBAC1 is lower, at my last review reducing my medication was discussed but we decided to leave. I am due my next lot of bloods and review. I do still slip but try to get back on the wagon again quickly.
I have found this more sustainable for me.