Throwing up undigested food 3 hours after insulin.

[Rachel & Link]

Hi everyone. My sweet boy link is 15 and was in diabetic remission for 2 years but showed signs again and I took him back for bloodwork and his glucose and fructosamine were high. We started him on 1.5 iu of Lantus just like last time but this time 3 hours ish after each shot he’s thrown up basically an entire meals worth of his wet food, undigested. He seems fine otherwise and will gobble up a snack or treat right after he throws up and has still had water today and probably kept enough food down to be ok with the insulin but I’m at a loss at what is happening. I called the vet this morning and they said if it happens again call back and bring him in but it happened again and it’s 10 pm. He does not seem hypoglycemic just a little sad . Any advice appreciated and I have extreme anxiety so try not to scare me please. Also he grazes on wet food all day and since being diabetic eats quite a lot so maybe just eating too much before a shot?