Do something warm when you are free. Don't eat too much cold food. You can also drink some ginger black tea (black tea can warm your stomach). When you sleep every night, rub your hands together and put them on your stomach and touch them clockwise 12 times and counterclockwise 12 times, and repeat several times, preferably with slight heat and moderate intensity.

You can also read more about this aspect of health care online. Perseverance will definitely improve. I wish you an early solution to your troubles!