I'd need a bit more info before I could comment with any usefulness for you. Can you tell us some or all of your:
Original weight (I prefer kilos but will convert them if needed)
Current weight
Height
Age
Gender
Type of diabetes
Time since diagnosis
Management (eg pills? insulin? neither?)
Latest Hb1Ac test result
There may be other things I want to ask but the above would be a great start. Beachbody Insanity training sounds kinda fun but I struggle to motivate myself to go for a walk, lol. I do know that the closer you get to the healthy weight range for your height, the harder it is. For me, weight loss has been easy so far - I've come down from a BMI of 45 - which is considered "extremely obese". I know it will get harder from now on, but I've got to keep trying.
Aside from the data above, if that checks out all ok then the next place to look for answers is to get a full medical check-up to rule out a range of conditions that could be throwing a spanner in the works. Our bodies are incredibly complex. But it's exciting when you solve some of the puzzle and can get healthier.