Definitely keep working on the eating habits. I've found that I feel TERRIBLE when I don't get enough fresh fruit/vegetables. Have a big breakfast before going to work, bring healthy snacks to work (so you can keep up the energy throughout the day), and drink plenty of water! Coffee can be nice when you first wake up, but it can't replace water. Also, be sure to continue those healthy eating habits throughout the week. Continue to eat breakfast, even if you're waking up later (by the way, it helps to maintain somewhat regular sleeping habits... so sleeping in until 9-10 may be okay, but until 12+ could throw you off), and limit your alcohol/caffeine/sugar consumption on your days off.

Little things kept me sane on my "long days" (which were generally 6 AM - 10 PM), like reading a book during my short breaks, or grabbing a treat from Starbucks after a particularly rough day. I kept up a routine during my "off" days (ex. buying groceries, doing laundry, washing dishes), but I also made sure there was plenty of time to do things that genuinely gave me pleasure (such as working on TeenHelp, reading, or watching my favorite TV shows). Finding the right balance could take you more than a couple of days, or even a couple of weeks. Be patient, and keep doing things that are good for your body (healthy eating, exercise, and adequate sleep). Everything will click into place eventually. If it doesn't, then you may need to look into other possibilities, such as your job not being a "good fit" in the long run (in which case, you can use your days off to hunt for new jobs).