Weight Loss Medicines

hello doc,i have currently been going through a series confusions,one of which is weight loss,recently i was tested for several stds and only found to be having chlamydia and oral herpes but i dont know why my weight keeps going down,i think alot about women around 21/24 hr a day but dont have sex,feeding;like two meals a day rice and chicken or less,and mustubating frequently,so am asking could my weight loss be due to the stds or the frequent mustabation.and could you tell me how i can help to gain my weight and get back to shape.thank u.samuel