Hi there ~
I understand your concerns and am glad that you have approached this website and asked your question on a public forum. The most common cause of muscle loss is the prolonged lack of use of a group of muscles. If you start exercising your muscles again you may regain the lost muscle mass. I do believe you are on the right medication for acidity and gas problem
and hope you are taking the medicine before meals. I also think that you might do well by visiting with a psychiatrist
or a psychologist
to help allay your anxiety
and explain your situation. Empathic listening also has the power of healing. I hope this helps.
Take care and have a lovely day!