Have you tried taking a daily journal?
Give a description of how you feel as a baseline, before you start the meds, and then describe your daily life in a paragraph or two - perhaps with a short rating (energy, attention, comfort, whatever else you consider important) at the end of each day.
Then give it a read at the end of the week or the month, and see how things have changed.
Its helpful to provide this to your doctor as well, if for no other reason than it demonstrates a good relative frame of reference and gives you something to key on more robust than "how are you feeling at this moment".
Chronic exhaustion is an easy side effect to pick up on, but you might not notice the presence (or absence) of subtler feelings down the line. So having them scribbled down day to day can give you a better sense of the relative effectiveness.