I've recently-ish started a regular, albeit quite light, weights routine. Strangely (or maybe not), feeling tired hasn't at all correlated with my ability to do the same number of reps and sets as when I'm feeling energised. The feeling of tiredness doesn't seem connected to actual muscle fatigue, it seems to be more mental tiredness, and therefore will power, or discipline, or mental strength seems to be more likely what's needed to get into an exercise routine.
Ie. Don't let yourself get away with saying that you're too tired, it's likely a different kind of tired than the one that will hold back exercise.
I've actually felt less tired coming out of a session than going in (endorphins, adrenaline effects etc.)
(with the disclaimer that this is very much a subjective, your-mileage-may-vary kind of situation, and also I'm speaking from entirely outside of your experience of always feeling tired)
I’m certain my mental health would probably be better with a better night’s sleep. Having only really started using the machine, here’s hoping!
Hope it’s helping you. Once I get some proper sleep I’m going to look into more exercise - which is surprisingly hard to do when you always feel tired.