Good afternoon Abby. Have you considered using calipers for dosing? It takes the guesswork out of dosing properly. It also helps with fine doses(.10u etc). When I was giving Moey insulin, I depended on those darn calipers. It takes a little getting use to but, definitely worth it. No more questioning the dose you gave. Here's a link to how it works.
https://www.felinediabetes.com/FDMB/threads/dosing-with-calipers-updated-w-videos.79851/
I was also using a light board/box to illuminate the syringe. Oh, how I loved that cheap $15 Walmart light board/box. It made it much easier to see the lines on the syringes for lining the calipers up. This is the one I used if you've never heard of a light board/box.
https://www.walmart.com/ip/TSV-A4-A...ng-Artists-Drawing-Sketching-Animat/502935665
I hope that opens up some options for ensuring proper doses. It eliminates the, "I think I gave him......
A fat 1.5, the plunger would line up with the bottom of the .5u mark, not the normal top position. Hope that made sense. I'm sure you've seen this sticky about insulin care and syringe info.
https://www.felinediabetes.com/FDMB...info-proper-handling-drawing-fine-dosing.151/ Towards the bottom of the page there's fine dosing information.
Once you figure the dosing method you're going to follow, that will outline how to proceed. After a fur shot or partial fur shot, dose increases need to wait for at least 3 days/6 cycles depending on the dosing method. 3 days is for TR. I hope this didn't confuse you. Maybe some other members will stop by to offer their thoughts/advice.
Cassie be good for mom! She loves you a whole bunch!

Have a great day Abby