Some people eat freely with insulin, thinking they can just cover the carbs by taking more insulin; this starts a vicious cycle of more insulin, more carbs and of course weight gain. You want to lower your carb intake as low as you can and lower your insulin dose accordingly. To do this you need to figure out your insulin:Carb ratio. Some doctors put their patients on set doses or sliding scales for their mealtime insulin and this also leads to weight gain. I recommend the book Using Insulin by John Walsh which teaches you to use insulin:carb ratios.
However that is a lot of weight gain and being that heavy makes diabetes hard to manage. Have you had your thyroid checked to see if that is contributing to your weight gain? If not, you should do so. Then you should talk to your doctor, or better yet an endo who knows a lot more about insulin use as well as weight management. Some type 2's, even after they start insulin are put on an oral med as well to prevent weight gain. Your endo can perhaps refer you to a dietician, but make sure they are talking low carb as many dieticians still follow the outdated ADA food pyramid. Low carb will not only lower your blood sugar which means you take less insulin but will help you lose weight as well.
THANK YOU THAT IS GOOD INFORMATION AND I WILL BE GETTING THE BOOK TOO