Even if you don't know the "right words" to say or the "right thing" to do, just letting your friend know how much you care about them and are willing to stand beside them and support them is a lot of help in and of itself. Don't diminish your importance just because you can't produce and immediate "fix" for them. It's a wonderful thing that despite your own pain and suffering you still want to reach out to help another. Many hugs!