T2 Diabetic, can’t gain weight even tho I use insulin shots

I got diagnosed with an A1C of 12, fasting BG was in the 400’s if I remember. I lost 73lbs and managed to gain back 14lbs over the course of 5 months but with massive insulin usage. I only need around 5-10 units per meal usually but I’m concerned as to why I can’t gain weight. I’ve actually lost 2lbs recently which is also very odd. Any other T2’s on here who can’t gain weight? Doctor took me off metformin a while ago and replaced it with insulin. Told me I would gain weight very quickly as I was also eating plenty of carbs. Just a little worried but haven’t felt weird!