Are you alright weird guy? If you are serious about being desperate then what i would suggest, bearing in mind you are only 15 years of age is either, and you will have heard this before.
1) Talk to a parent/brother/sister/grandparent.
if you cannot do this.
2) Try approaching a teacher, neighbour or friends parent
if you cannot do this.
3) There are many organisations available for teenagers with deppression or problems with everyday life and can always find a better solution.
These include: Teenage, Youth to Youth, Samaritans.
You will find a lot of help on this page. (follow link below for helplines)
http://www.google.co.uk/search?hl=en&q=teenage+helplines&meta=
If as you say, you are desperate then i hope you find the help you need.