Living with someone who is depressed is one of the loneliest feelings in the world. You're trapped with someone you know you love, and yet the only side of them you see makes you miserable and confused. There's plenty of help out there for your partner, but what about you? How do you cope? When Caroline Carr's partner of 20 years became depressed, it was a shock. But slowly she learnt the techniques she needed to cope without being dragged down