In my many years of living I have found that the best pick-me-up for depression is to get your mind off your own problems and do something to cheer someone else up. If nothing else, send a card and make someone else's day a little brighter. When God lays someone on your heart, there's a reason behind it. Pray for them and act on his leading. You'll feel better and so will they. Trust me - it works!
Keep a diary of your sleep habit and what you eat. What is causing the most stress? Good days need to be in detail, because things are happening to make you happy.