JonJon92,
Try deodorant or perfume or baygone(joking!!) to get rid of the
extra smell, and drink more water.....consume less tasty food, eat
more vegetables and fruits.
And please shower often! 
Even though if you managed to get rid of your body odour, I
don't think you can redeem back your self-esteem.
You must first like yourself before other people can like
you.
Smile often, practise in front of the mirror everyday and remind
yourself that everyday is a brand new adventure and you are waiting
to find out what awaits you for the day.
Look at your smile in front of the mirror and see if you are
impressed with your smile or not...if you're not even attracted or
impressed with your own smile, then you definitely cannot attract
people who want to befriend you.
Have a great smile of your own signature, and flashed it
everynow and then whenever you talk to people or people talk to
you. IF you can be attracted and impressed with your own smile,
then I can tell you that you will be able to attract many
other people out there who doesn't possess the same attractive
smile as you!
We all have our own talents, pick the talent that you're most
capable in doing (please don't tell me it's sex or masturbation)
and dwell on it everytime you think you are about to feel down.
If you really have no other talent but only sex and masturbation
on your mind, then by all means go and dwell upon that and be happy
with your talent. But don't go and tell people what your talents
are, cos nobody want to know about it...including me!!!
Holy gosh ! What has this to do with sex and masturbation? And
self esteem is not something you can't redeem back. What you think
it is ? ICULS?
Self esteem is what you think of yourself. People stay away from
people with low self esteem. I really think that we need to give
this kid some good advice - teach him that self esteem is something
he can develop and appreciate himself better. Remember JonJon92, it
is not a sin when people look down on you but it is a sin when you
look down on yourself. Think big !