I used to have the same issue and one thing I have to tell you is absolutely do not think about removing medications on your own, or lowering the dosage. I know you most probably already know it, but this is a reminder it will only worsen things.
That being said, do talk about this concern with the doctor or psychiatrist who prescribed the medicines, take note of which medications you think could be the main cause of your lethargic feeling. Don't be afraid to insist on the fact that the medications are making you feel tired, a good doctor would take note on that and either lower the dose or give you "lighter" prescriptions; since the doctor's objective is to help you live a regular life, their medications should not be an obstacle to that.
About the low energy, feel free to rest as much as you need, but keep your brain active with activities that don't require much energy, such as puzzles, or origami, or drawing if it interests you.
