This sounds like what I had with Carson. 11 yo male, 19 lbs then lost weight and drank a ton. Diagnosed diabetic 11-27-17 and started on Lantus 2 units bid. Started not eating 12-11-17 pm and 12-13-17 had hepatic lipidosis and hospitalized for 5 days. 12-2o pancreatitis pain set in as we couldn't dose him orally with pain meds. It ends up on me or the floor. Went back to the U for 3 days. We got pain controlled with fentanyl patch til wore off then back to the U on the 28th and got a pain patch scrip. Yes the pharmacist looks at you like you're a criminal because it's a controlled substance but my cat needed it so whatever. Doubt he's running drug deals from the litter box. He's on 1 unit bid eating grain free pate and hills md dry to snack on. Insulin shots- I feel like an a-hole for poking him with a needle twice a day but he and I have an understanding that this is not negotiable and he gets food before and treats after so I think we're ok. Glucose curves have been hit and miss- start 2 units, then 1, then 1/2 now 1 prescribed. I probably am conservative as far as volume of food I need to see him eat before a dose as I work 35 miles from home so can't watch him for hypo. It's hard to be a diabetic cat mom but he's my baby and I have to do it to keep him alive. That keeps me going. He's still too skinny though and trying to get him calories.