You're most likely thinking that it's easy for us to sit here and type 'BE POSITIVE' over and over again. You'd be right, but it is true.
Last year, an uncle I was close to died (and his wife + children made a spectacular mess of the proceedings which hurt us even more), I got fired form my job for a stupid remark that someone took seriously, and someone I thought I loved broke my heart.
At this point, I was well and truly down, but it did me the world of good. I got to know myself, realised that money is just paper and metal and had some great times.
The most important moment was when a friend who I hadn't seen for years got back in contact with me. He'd left our school in 4th year because he was starting fights with a lot of people. I found out that he could have had full blown schizophrenia if he'd been left untreated for another year.
It was depressing to see him at first. Due to medication and his fears, he has become very child like in his mannerisms and is extrememly naieve. But he made me realise that there are people worse off than me, so I'd better make the most of it. That was nine months ago, and he's started coming out for nights out in the town, which he would never have contemplated even four months ago.
Another changing point was when I was searching for a picture of Lee Harvey Oswald for a joke. I typed his name in on Google, and there was a picture of the 1981 exhumtion. It was a picture of his head. As you can imagine, it wasn't in the best of conditions.
It horrified me, but it made me realise one thing: when the body goes, that's it. No more.
That filled me with a lust for life. It put everything in perspective for me. You've got to cram so much into your life, so you can say you've lived.
Long and rambling post, but my message is simply: when the body goes, that's it. No more. So do something.