Hi Tyleena,
This reminds me of something I recently went through, where someone started confiding a lot in me (can't tell you what as it was in confidence but real sad stuff) which made me spill all these dark secrets which NO ONE apart from me knew before. Everything from attempted suicides (when it came down to it I just couldn't do it, yes I'm that pathetic) to home and personal issues. So I do understand a bit of what it's like. Though not abused by family members certain conditions that my family have but lots of stress on me and have made be more depressed. As for personal, bullying mainly and lack of any self confidence.
Talking can help, I'm serious. I'm not sure if the girl who confided stuff in me has talked to many others but I feel that I've helped her and she's helped me just by talking. (We do not know each other in real life, she lives 1000s of miles from me). This in a way appealed to me as if everything went wrong and she took it the wrong way or I suddenly regretted it I could cut off contact easily. As well I am a loner, can easily spend school holidays never seeing people form school etc. doesn't bother me much.
Anyway enough bout me, was just saying that to relate a bit.
So yeah, can you trust this other person you kinda want to tell not to overreact? Not to go bout spreading it? And above all be supportive and understanding. To me they sound very sincere about wanting to help you or at least understand what's going on. I'd say go on tell them, but only if you are comfortable with them knowing. If they already know about your self harming it is probably best to tell them the whole story, they may tell others who would try and "help" you as they don't understand themselves why you do it.
As for songs, I find that rock and metal often conveys these sort of emotions or stories very well. Other genres can to but there's just the raw emotion in the lyrics of rock (emo especially I find) which drags it out for me.
So here's a couple.
Hurt by Nine Inch nails, this one relates to loneliness and self harming I think. Listen carefully to the lyrics and the way they are said. http://www.youtube.com/watch?v=AvJKVKglIRs&ob=av2n
Another self harm song, lyrics are powerful but also speak of home about being saved. http://www.youtube.com/watch?v=fKuzaPV-af4
This one makes me laugh a little as one of the suicide attempts were stopped by someone seeing me, it was a young child I couldn't walk off the cliff knowing she could see me it just didn't feel right. Then by the time she went the moment was gone.
Anyway here it is, it might not apply directly to you but it's worth listening to. http://www.youtube.com/watch?v=gEyQI7tmkG4
This one also relates to what you've said. http://www.youtube.com/watch?v=diaHnF-zfEg
Also this: http://www.youtube.com/watch?v=wsqKH_VIrng&ob=av3e
http://www.youtube.com/watch?v=lL2ZwXj1tXM&ob=av3e
This one is quite different to the others, but I've listed to it a few times and it helped me once or twice just like these other songs.
http://www.youtube.com/watch?v=MUfgAbFY4CA
This one might go with the family problem, I haven't experienced this much so can't reccomend many sorry. http://www.youtube.com/watch?v=He4UYikvGBs
A bit more upbeat http://www.youtube.com/watch?v=ENwIVw2h3SQ
I hope these songs and what i have said can help you in some small way. I wish i could do more, I always do.
I advise you to try and get help, tell other family members what that persons been doing to you, there are many ways of abuse physical gets too much attention nowadays, the psychological damage can be worse for that you need support. If you tell your friends, see if they would be comfortable supporting you in telling the rest of your family, or even better a Councillor or even a teacher, anyone in a position to help you really.
I hope things get better for you, I mean it no one deserves this.