Heather, welcome to you and Scooter. I tried to catch up on original history, based on your first post in the health forum, and I also wanted to encourage you to make sure you are using the correct syringes, which was previously mentioned in your first post. Because we generally make dose adjustments in 0.25u increments, you want to make sure you are using U-100 3/10cc syringes with half unit markings.
Insulin Care & Syringe Info
This picture from the sticky above should help, hopefully it comes through
View attachment 59849
While it is possible to have kitties react quickly when starting insulin, the numbers you had today make me wonder and I am worried you may have given more than 1u, if you aren't using the U-100 3/10 cc syringes. The other thing I'm wondering about, can you tell us a little about how Scooter was diagnosed with diabetes? Was he showing symptoms of diabetes? How was he diagnosed? Did the vet run any blood work and urinalysis, or fructosamine? What are you feeding Scooter? Is he on a low carb wet/canned food, or do you have dry food in the mix?
There is quite a lot of information here, and people who are happy to help if you have any questions. A good starting point is this post:
New? How You Can Help Us Help You
When people here on the LBL subforum are new, and just gathering data and experience, we recommend if you get a preshot number 150mg/dL or below, to stall (don't feed) and post for help. Continue to recheck in 20 minutes to see if the BG is rising. On the main health forum, we usually suggest not shooting if the number is below 200mg/dL, until you gather enough data and experience with how your cat responds to insulin and carbs.
Perhaps you can take a picture of what you believe is 1u on your syringe and post? At this point, given the cycle he had today, regardless of the dosing methods that we follow here, a reduction to 0.75u is warranted.