I truly take heart in helping people as well. I was depressed once and I honestly don't want people to go through it like I did. However, while it's a good thing to do, just be warned there are bad things that can happen. First, it's okay if you do it because it helps you, but make sure you have heart when helping people. This is just a general thing you should do. Don't help people just because; do it because you actually want them to feel better.
The main thing here though is that if you help too many people it could actually have a reverse affect on your depression. I have gotten even sadder before merely because people's problems weighed down on me so much after a while. This can have a pretty bad impact on you and no one will feel better. So, just watch how many people you go after. You don't have to help absolutely everyone on here.
But that aside I think this is really great of you. Just treat it carefully and you'll be good! Also, I hope you get over your depression soon. Just hang in there!