A couple raw eggs blended with some chicken livers and okra immediately before flight always worked well for me
Seriously, back when I was getting my ratings I had a couple of flights where I didn't feel that great. Many of us have been through it and most likely it will pass as your body adapts. Try some dry toast or crackers and some water or ginger tea before you fly. Ginger ale works but watch out for too much carbonation. Avoid greasy/acid/dairy foods before flight until you get used to it. If you're flying in the morning I would skip the OJ and fried stuff. Go with some toast or a granola bar and make sure you stay hydrated with water or weak tea. A totally empty stomach can also cause problems.
Many people don't believe in it but I have found that the pressure point in your wrist works very well to combat nausea, and not only the motion sickness kind... Take your
left wrist and find the two hard tendons in the center of the inside of your wrist. Apply strong pressure in between the tendons about one or two fingers width up from the base of the wrist. Apply pressure for ten to twenty seconds at a time, release and repeat while taking slow deep breaths.
Hope that helps and good luck.