What can cause nausea, fatigue, light headedness and hot flashes not related to menopause?

I am 20 years old with a 5 month old daughter and I have been expiriencing these symptoms for at least a month. I randomly get nauseous...nothing specific sets it off. The hot flashes are also at random....I always get light headed when I get up from laying or sitting to the point where I have to stop moving and hold on to the wall or something until it pes. Yes I have a 5 month old daughter but she just got out of Primary Childrens Hospital on Dec.17th and I had major fatigue before she came home so I know that its not just from getting up at night. I do not have health insurance at the moment so I am trying to figure this out on my own rather than going to the doctor. Any ideas??? Thanks.