oh gosh, you've really had a time of it. wendy is absolutely right - ALL of us react like you did today the first few times. don't worry one moment about it.
this is likely still from the previous dose - it can affect numbers for as many as 3 days, although it lessens and you hopefully won't see this tomorrow.
to make it easier, i'll sum up' the rules (I'm a rule-follower too!)
if the BG goes below 50, pop open a can of high carb canned food with gravy, squeeze out the gravy only part and give 1tsp.
wait 20ish minutes, test, and repeat if necessary.
lather, rinse & repeat until numbers are staying over 50 for 2 tests AFTER you've stopped giving carbs AND the cat is past their nadir. i usually kept it up til i saw a 70+, and had stopped giving carbs at least 45 minutes before that, and it was past punkin's usual nadir.
gravy can upset some cat's tummies. you might do better with karo syrup. you don't usually want to feed the food with the gravy only because most of the carbs are in the gravy and you want ophie to stay hungry enough to eat the gravy on her own. you might try karo next time, just in case the vomiting was from too much gravy.
if she won't eat, you can rub karo on her gums or use a syringe without a needle (the kind meds are given with) to squirt some in her mouth. if you are desperate, she won't eat, you can't get it in her mouth and/or see symptoms of a hypo (low numbers do not equal a symptomatic hypo) you can use a needle-less syringe (same kind) to put karo syrup up her rectum. mucous membranes will absorb it. if you get to that point, head for a vet to get a glucose drip. you're not at that point, and i have only once known of someone having to go to a vet for help with low numbers, but always know the option is there for you.
just thinking ahead to morning, if you are faced with a less than 100 again, you might want to just give a token dose, perhaps .5u, to allow the depot to drain so you're not doing this again tomorrow. then tomorrow night you may be able to return to a larger dose, depending on what's happening. people will be looking for you to see if you need help tomorrow.
you really are doing a great job. i hope she's done soon and you can sleep tonight.