Grob Queen, are you sure your problems have to do with g? High g causes blackouts similar to the feelings you can get when suddenly standing up after a long rest or a hot bath, or suddenly stopping after a dash, but these are very unlikely for a healthy person experiencing a 2g overload (60° turn).
On the other hand, nausea is caused by Coriolis forces and/or a visually perceived rotation. You can train yourself to overcome it, but the first thing to do would be to eat the right kind of food before the flight: don't fly on an empty stomach, nor immediately after a hearty meal. Many pilots doing scenic flights recommend their passengers to eat protein-rich food (like steak and eggs).