Try drinking some ginger tea after your meals or when ever you feel the gas building up. Ginger is very good for relieve of both nausea and flatulence (gas). You might also try mixing equal parts of cumin, coriander, and fennel seeds and making a tea of this mix (1 tsp to 1 cup of water) to drink after meals to help balance your digestion.
The symptoms you are describing, the panic attacks, the trembling and weak muscles are all signs of an aggravated Vata dosha, or wind energy, in energetic medicine. I've posted a few links below to sites give an overview of ayurveda and vata dosha. See if you recognize any of the other symptoms.
I also recommend Andreas Moritz 's book The Key to Health and Rejeuvenation. It is very easy to read and explains the energetics of the body in an easy to understand way.