Can anyone give me some tips/help me with my depression?

[David]

I have good family good friends i guess.... yet i always feel so alone, all my life im almost 18 now so i know it may be some ridiculous teenage depression but i am lost i feel so numb all the time I feel way mature and not like anyone from my age group and I have really bad anxiety and feel breathless sometimes when im at school. sometimes i'm just standing around with friends and just space out listening to music and then i feel like i just want to be alone.... i'm at home and i barely want to talk to my parents cause i want to be alone and then I feel soo lonesome so i talk to my many friends that i have over facebook and sometimes it becomes overwhelming and so i stop talking to them or take a while to reply and try to distract myself with video games and things.... I don't know really what exactly is the cause maybe it's because i listen to really depressing music all the time? yet music is the only thing that really gives me comfort..... I work out every other day, drug free, and occasionally drinks but nothing really helps i do tend to not tell people my feelings and things cause that's the way i am although i have talked about my problems to some people but that still doesn't really help out much oh and now i have this skin condition that will come and go for the rest of my life and there's no cure apparently just ways to help the annoyances and that has really been killing me recently just cause it really sucks..... But if anyone can give me some tips anyone whose gone through some struggles or anything i'd appreciate it.