One of the first questions is ar eyou eating enough? If your calories have seriously dropped down, the excess acid in your stomach could be contributing to it. Secondly what kind of suppliments are you taking? When I was using my prenatals as a multi vitamin, I had to take them at night to reduce chance of nausia. If you aren't taking suppliments you may find a multi vitamen could even help with nausea and blah feelings. Many also take calcium/magnisium/potassium to help with symptoms such as lower energy, fatigue, light headedness and so on.

And the third question, which usualy gets me hit with a phone book, are you pregnent?