hi ! smegma is formed due to secretions of penis, its important to clean regularly as if it remains for longtime, it creates offensive odour and causes slight itching too. esp it is also seen when u dont wash your part after masturbation. you have said it is the white layer for which you need not worry about, if it is yellowish or greenish then you my need to consult a physician. regarding your wt, you have dropped 5kgs with in 2 mths, there are varied reasons for wt dropping - night shifts, tension much, sleep disturbance etc, etc. consult a good physician near by and share all ur symptoms that you r noticing, he can help you with proper diagnosis if there is any. as per your present condition there is not much any trouble as you have no associated conditions other than wt drop. just concentrate on your food ad observe couple of weeks, if your wt is increasing you need not worry about it.

It's balanitis Please consult urologist online or near you for proper diagnosis and treatment