My sainted wife and my damned passion

So I have a long awaited bike trip to st george tomorrow. I am going to ride in an amazing place with small army of riders I don't know. New friends, new trails. People drive down from BC to ride there. Bike companies test new bikes there. It is famous, a grand cathedral in the church of spinning wheels. A definite bucket-list worthy place to ride. I should be psyched.
But I'm not.
My wife has been kicking butt nonstop for weeks while I go to school and work. She has had some time to herself, but not much, and in the last week she has had almost none. I work hard too, but she is juggling the kids by herself with almost no spousal support. I work nights and go to school in the morning leaving the afternoon to sleep. During that time she gets the kids up, feeds them teaches them, takes them to karate, cleans house, does the shopping, and keeps them quiet so I can sleep. The only time I am home to pick up any slack is the weekend, and this time I will be gone meaning the hard week will continue into the next.
She is the one who deserves an epic vacation, but I don't know how to give her one. The best I can do is look forward to this summer and try to make it up to her.
In the mean time I just sit here feeling guilty, wondering if I should cancel my trip.