Pick your hobbies around their activity level. Rather than sitting around and watching television for entertainment, get an audiobook from the library and take a long walk. Stretch out your new leanness in a yoga class. Learn to build things, or get started on some of those DIY home improvement projects you've been meaning to do. Even something as simple as taking the stairs at work or parking far away from the entrance in the store parking lot adds small bits of physical activity to your daily life that add up over the course of the week.
MyFitnessPal: An app widely recommended by trainers and fitness enthusiasts, MyFitnessPal is great for tracking macros. Goal macros: 50% carbs, 30% fat, 20% protein. It further breaks these general guidelines into specific gram amounts that make it easy to see how some macros add up quick (carbs) and others don’t (protein — hitting 64 grams takes conscious effort!).
One source of fatigue from altering one's diet is trying to cut out too many favorite foods at once. You can develop a taste for healthier foods and lose your sugar cravings, but it's not going to happen overnight. While it might be tempting to raid the pantry and throw out everything that's bad for you, that's not the way to create lasting habits.