Hey,
Being tired is normal - also with your profession it will kick your butt. You have to realize that you did have surgery and your body is adjusting to the change of food intake also. But you really need to follow the program on the stages. It is this healing time that will help with ensuring that your band will stay in place (by allowing it not to be working digesting) during this early recovery time.
With your job, it will be all about planning.. I know it is easier said than done. However, you have invested the $$ and the time for the surgery - give yourself the care you deserve.
I know when i had my surgery 2 yrs and 135#s ago, it was 2-3 months before i was back up to par.
Sounds like you will have to look for things that have high protien in small quanities so you can grab and go. Which for me is was part of my wt problem to begin with. Eating on the run/drive/walk/sitting LOL...
Just know that you will begin to have MORE energy than you had before but now your body is recovering.
Good Luck!