Hi, Welcome to Health care magic forum.
As you describe, you are very much interested to gain muscle, and could not get it.
If you try whole hearted you can get what you want.
I advise you to consult a physician for diagnosis and treatment .
I usually prescribe to my patient with such requirement injections of
anabolic steroid,periodically,
protein supplements, preferably proteinules, enzyme preparations, and multivitamins.
Take more of green leafy vegetables, pulses, sprouts, and protein rich foods.
Practice
yoga, morning walk, and do any work in front of you.
Wishing for a quick and complete recovery. Thank you.