I think everyone is so different. For me, I don’t usually see much change in my blood glucose in a 23 hr fast. That being said, I fast regularly, both intermittent and longer, and I keep in mind that my insulin levels are lower by the end of any fast. You need to remember that shorter fasts give results by being repeated, which you said was not an option. the results just come slower.
Have you considered intermittent fasting by just shortening your eating window? There is enough info out there on the benefits of just eating during a 6 hr window as a daily life style. There is also information about just eating 3 meals a day with no snacks. Yes, these all take longer, but would be consistent with what your meds allow.
Since I assume you are on these meds for a reason, I would not advise you stop them I order to fast. I would rather, if you want to fast, you find a way to work the fasting around them.
I am also assuming you have tried a low carb possibly Ketogenic diet. If not, I would look into it. Especially since your meds already increase your glucose and require meals.