Hello dear,
First of all, please do not make hurry in gaining weight.
The metabolism of the body functions at its normal rate & any measures taken to hasten up this process can be harmful.
Regarding
masturbation, it is a normal physiological process & does not have any physical or mental effects.
The acne are caused due to blockage of sebaceous glands on face with super-added infection. It can be taken care by
benzoyl peroxide & a course of antibiotics. Kindly
consult a Dermatologist for the same.
Moreover, you should not compromise on regular exercise & routine healthy food such as:
1. Consume more of natural diet like fresh fruits, green vegetables, milk, eggs, wheat, etc.
2. Avoid oily and junk food.
3. Stay away from smoking & alcohol.
Despite these measures, if you experience difficulty, it will be better to rule other causes of
underweight.
Investigations like
complete blood count, thyroid profile, estimation of blood sugar level will be helpful to rule out any chronic infection, hormonal and metabolic causes.
Wishing you a healthy life.
Take care.