Hello, You are just about to complete 18 years. You are in adolescent age. You say that you have lots of pubic hair and your voice has deepened - meaning your hormone secretions are OK. Your problem is the penis size, sexual performance and its relation to obesity. Obesity has some problem with sex, but not on the size penis. You say that your penis is small as though it is buried. See, it is only an illusion. For example an individual who is thin with a small penis, may look like having a big penis and an individual who is obese with a big penis may look like having a small penis (because of the larger size of the body). The buried look is because of the fat surrounding base of the penile shaft. When pubic hair is removed the penis may look like bigger than before. So you understand that obesity has no impact on the size of the penis. If you reduce your weight it may look as though your penis has grown in its size. Moreover the size is not an important factor to please a woman. But the points - you have to understand. Obesity decreases the sex performance through other ways. 1) Obesity decreases the stamina and confidence 2) Obesity increases the depression Investigate the cause for obesity (like thyroid) and treatment accordingly Consult a dietitian and adhere to the diet advised. Leave your inferiority complex You are normal in all aspect and wait for sex for some more years. Now concentrate on your studies Best wishes