Hello,
There are a varied list of causes of the symptoms u mentioned .
But what is more annoying to you?
Ur non muscle gain as u said can be due to nutritional or organic causes .
But ur weight for height is OK,so can't be nutritional but can be absorption defects due to varied causes or any organic causes which requires thorough examination.
Regd.
Anxiety it can be
hyperthyroidism but we require other symptoms which is not given here.
But
tsh being normal can be unlikely .others causes leading to it must be ruled out.
Regd . low sexual desire,are u on any other drugs must be taken into consideration.
But looking from far away,I opine that the case is non organic.
Instead of brooding over getting diagnosed, kindly do
yoga for 3-4 hour daily or running 4-6 km daily,endorphins and corticosteroid s will be released which causes reversal of all your symptoms and increases your sexual appetite, i am sure that u will reply positively after 1 month by following the precious advice.