Do you need to eat with the medication you take at night? If not then I would eat breakfast and lunch and skip dinner.
You could also ask your dr if the morning meds could be taken a little later in the day. Many can.
I have a similar situation. I won’t pry as to the medication or if there is leniency, but I tend to take the morning one a bit later and the evening one a bit earlier. Not ideal obviously, but I’m not going to sacrifice my health for the sake of a couple extra hours of fasting.