>>2 100% agree.
I thought I would give my insight, considering that I'm actually in the same position that you are! Or, I was. I've had friends who have self-harmed before, and it scared me a lot because I didn't want them to feel so bad as to do this.
I know there are alternatives to self-harm, and I tried to support them by showing them that. Some of them were appreciative of it, while some of them didn't really want to talk about it. It depends on the person, I believe, so I would definitely take
>>2 's suggestion and read up on it.
All you can really do for someone who self-harms, I've learned, is do your best to support them.
Never grow angry with them for it, and don't ever push them into discussing something that they don't want to discuss. If they are someone you truly care about, you have to try and understand regardless and be there with them through their struggles.
Three out of five of my friends are now x-years clean, and one is on her way to recovery. I really, really hope that the both of you have such luck. ;u;