Re: SO tired the week of my period...
Threethings is correct. During your period it's extremely important to combat the symptoms with some good old fashioned clean living.
One major thing that helps is exercise. Get out and take a walk. I swear, it sounds stupid, and the last thing you usually want to do is move. But I promise it helps give you more energy.
Get hydrated! Make it a point to start drinking water whenever possible. Strive for 64oz a day. Cut out the pop if you can, and substitute with water.
Try to eat well. The phrase "you are what you eat" is so true.
Basically you should be doing things you would be doing anyway...but make it a bit more extreme. If you usually drink water...drink more. If you usually exercise, go an extra 20 minutes. Or split up the exercising into two times a day (work out at some point, then take a walk before dinner). Just make it more pronounced.
If it's still not working, then talk to your doctor. They may be able to give you a good vitamin to take, or maybe just tell you to take a mydol. Sometimes that's all I need to help me get out of my armchair.