change your diet. get fats and heavy oils out. keep starches low. keep simple sugars low. keep calories lower than you're used to, but not starvation level (like for most people around 1800-2100 calories will be fine). in doing this, reduce your portions. you probably eat like i used to: inhalation. no good. take your time. eat very slowly until you stop feeling hungry, and no more. never eat until you feel full. that will turn into fat and it takes a tremendous amount of energy to metabolize it all into energy storage. this is a huge part of what will make you stay tired all day.
actually count calories. eliminate sugary snacks from your diet. no candy, no soda, etc. this step counts tremendously. you'd be surprised how direct the link between junk food and no energy really is.
drink water. try to get right around 64 ounces of clean water a day. i usually have 48 ounces. what i do is carry a 24oz water bottle with me and just make a habit of occasionally sipping it. you'll find you can go through it twice in a day without paying attention.
i even eliminate one meal. then start forcing yourself to get up at the same time every day. doesn't matter if it's 7 or 1. when you're getting used to it, pick a time to go to bed. again, doesn't matter if it's 10 or 2. hold yourself to it every night, though. try to get between 7.5 hours and 9 hours every night.
now, this is the part i can't ever force myself to do: figure out a good cardiovascular workout. jog for half an hour, until you sweat. try to get your heart rate around 150 beats per minute and try to sustain it for 15 minutes. at least five days a week.
you'll start to see a difference within two weeks. if you do it right, you'll feel hungry for the first few days, but as you get used to it you'll start to notice a few things:
1) your appetite is easier to settle
2) your energy is up, from the moment you wake up until the minute you fall asleep
3) it's easier to fall asleep, and easier to wake up
4) your mood will generally increase.
5) you will immediately begin losing extra body weight. if you really are exercising, though, only the bodyfat will come off. it's mad splendid.
g'luck!
~ dan ~