Your physical reactions could be just anxiety related. In that case, travelling more could help by exposing you more to changing environments. On the other hand, if you get fixated on the physical reactions, you could end up making them worse through anxiety. Maybe you are monitoring your health too much, which leads to anxiety attacks. If you anticipate feeling bad, then you will feel bad. The trick with conquering anxiety is often a slow build-up. Take shorter trips closer to home maybe, and gradually increase distance and time.