What to say?

First, I would like to thank you guys for all being here. Everyone is so supportive and I am learning so much from this entire site.

My question today is about two very important people in my life who suffer from depression. My boyfriend had only minor depression after the death of his father and my horseback riding coach is right now going though a major dark time.

I was wondering if you guys can suggest to me what I can say to them to help them through this and also what I shouldn't say.  I have learned alot by just reading everyone's responses on here by what the supporters say to the one in need.

My coach is the difficult one for me. When he talks to me, I just feel so useless. I don't know what to say to him. His depression deals with inner demons way bigger than I can even imagine. He helps me with (what seems like now) my miniscule problems in my life and has been a huge influence in my life and my outlook on things.

This morning he opened up to me more than he ever has. Here is basically what I said to him:

I first told him how he is such a great friend to me and appreciate everything that he has done for me. That he has turned around my life and I am such a better person now because of him. I told him that he helps so many people around him and that he is allowed to feel this way.  I told him that I wish I could be the friend to him that he is to me in regards to helping through hard emotional times. I told him that I will listen and will do anything for him that he needs to help him through this.

He appreciated me saying all that to him (and he knows how hard it would have been for me to say all that cause I have openness issues of my own!). But when I got off the phone with him I just cried. He ALWAYS knows exactly what to say to me when I have problems, but I can't do the same for him. He really is alone in this. I have him, but when he needs someone, there is no one.

Thanks for any help you guys can give me, I'm lost.