I think you are just not getting enough sleep. I'd bet that the on the 10 pm days, you're still tired from the late nights, so you don't feel completely refreshed. I'd say to give it a try, commiting to go to sleep at 10 every night for 1 week. If that cures the problem, then you can experiment with how much sleep you really need. The other thing to try is making the mornings a bit shorter. have 1:45 from the time you get up to the time you leave is a lot of time. Maybe you can shorten that some? Also, maybe take a nap at lunch if there's a place to do it.

If all of that proves untenable, then i'd suggest just planning on riding only 3 days a week. M-W-F & taking the other days to refresh. Eating healthy and drinking caffeince will help, but if you're only getting 5:30 hours of sleep a night, but need more, you'll lilely always feel lethargic.