Hi, and welcome!
I do get tired at times during the day even when I get enough sleep. I’ve kind of assumed that it was a fairly common thing, since the “5 Hour Energy” ads mention that people get a “2:30 feeling” of being tired. Then again, I have a very inconsistent sleep schedule, which I hear can make you tired even if you get adequate sleep.
As far as medication, I’m not sure if I have an answer, sorry. Keep trying things!