I have a friend who is rather self-destructive. I am her second friend and I managed to help her to open up to more people and have more friends etc, but some months later fights started breaking out between her and the others, with the peek of it being a fight between me and her. I know it really hurt her considering she had had a fight with her first friend some days earlier.

The question is, I don't know how to approach her now. The things that were said during the arguments were pretty heavy and very hard to get past through. Should I let her sort some things out first and let her approach me again when she is ready or just start talking to her again?

It's good to talk to your friends after a big argument. If you wait too long to talk however then you may just make the problem worse. Definitely try talking to her when you can but make sure this doesn't turn into a big fiasco of "Whose fault is it?", try to have a nice calm conversation talking about what happened. Try and understand both your point of view and hers. There may be a reason to why she's been having such a short fuse lately and who knows what that may be (school, family, etc.).

I hope this helps you out.

You should talk to her. You should clear up any uncertainty and let her know that you do not hate her or that you are angry with her (don't bring up anything specific from the fight). After a simple apology. She is probably feeling the same way you are. Maybe you should even try to find out what the problem has been lately.

Hope this is helpful