Whether you can do anything yourself to help stem the nausea depends on its cause. I've had similar problems - but with actual vomiting. Nausea is a pretty non-specific symptom that can have a multitude of causes. Given that the nausea hasn't actually led to vomiting, I would take that as a good sign. ~30% of the population have a hiatus hernia, which can lead to reflux of stomach contents and subsequent feelings of nausea. As Groupie said, a trial of a proton pump inhibitor might make all the difference. It could be as simple as that. It's definitely a good idea to get yourself down to your GP and have a chat about this (and rule out other possible causes). If you don't like your GP, ask to see another one; or changing practice is pretty simple. Just ring up the practice to which you'd like to migrate and ask what you need to do.
It is important to note that the subjective feelings of nausea result from activity of the CTZ in the brain, which receives signals from both the gut, other parts of the body and other areas of the brain. Feelings of nausea are common before job interviews etc. Therefore, although it may not be a cause of the nausea, anxiety can certainly make it worse. Therefore, it makes sense to ensure that "your house is in order" and evaluate whether there is anything in your life that could be causing you stress. Taking time out to relax can't do any harm. Also, because nausea is unpleasant, it can cause stress in itself, thus making the nausea worse, and causing more stress etc. Therefore, a calming distraction when you are beginning to feel nauseous can help a lot. Making sure you're getting enough sleep, eating healthily and regularly can make a world of difference to how you cope with this symptom, until you find a cause; it sounds really simple, but pretty much everyone gets this wrong from time to time.
It might be worth thinking about the times that the nausea arises. Is it at a certain time of the day, or associated with a particular event? Is it made worse by eating, or better? Do you have any other symptoms?