I'm of a bit different mind that the others. No one has asked about what elevations you live and train at in comparison to your high alltitude mountain passes. I live at 5400 ft and ride 5000 miles a year. I have also done some high mouintain tours with a ton of elevation gains at very high elevations. I don't want to be negative and rain on your parade but I would guess if your doing much high elevation training your going to suffer as you get deeper into your event. Riding a few 50's back to back to back on the flats in town is no where near climbing over high moutain passes day after day with all your gear..
If your not getting much altitude training during the week I would cut down on the days you do ride and on the ones you do ride, If you can I would get up in higher elevations. Also as beat up as your already are I would start backing down maybe 10 days out so you can be as rested as can be when you start your event. Your not really going to build any more fitness in a few weeks prior to your event, even if you killed it all the time.
So like the others have said sleep all you can and get rested before your event. And I would add ride less and do it at higher elevations if you can.