It is possible that you are just not eating enough, esp. if you are feeling sick while working out. Your body needs more calories, ie, energy!

I suggest seeing a dr to get an ideal weight set for yourself and to tell him or her your workout schedule, diet, and how you have been feeling. Most likely a good multivitamin and more daily protein (which can be quite filling) each day will do wonders for you! Make sure you are drinking lots of water too, and drink something like Gatorade since you are working out that much.

Do see a dr. when you can! I wish you the best!