I feel for you. I had a period I was exactly feeling that way. To be honest I'm not sure if I "got it back", but at the very least I've managed to "get" one. I've found things I love, and things that move me. Maybe not what you'd call a proper "dream", but I never had that in the first place.
I think what you should do is start to find your own self. Experiment. Find something you like. Be aware of your every movement, don't just perform it mindlessly. Don't expect too much from yourself, set up things you have to do and that you can do. Take it slowly, don't rush.
And most important of all, try to remove these negative thoughts. I've been there. Still am, in part. Those thoughts are the ones that make you feel down the most, and get you depressed. It helps me thinking something like this "I may not <insert bad thing here>, but with time, I'm going to improve".
You'll see.. by living you'll find a purpose in life. Or at worst, you'll meet some person it'll be worth staying alive for
And remember, your life is your own. You are a different entity than other people. You are you. And it's good that you're different, even if in thoughts. It'd be a pretty boring world if we were all the same.
So, even if you feel depressed, try pausing, breathing deeply and clearing your mind of thoughts. Then slowly, start working on the small things you can change, on what you can do. Slowly, but surely, you'll get to the big things too. In time.
And comparing ourselves to other people I feel it's wrong too.. as we compare the enirety of our lives, our joys, but our sorrows too, with just the best we can see in them. And everyone suffers at times. It's inevitable. Hang in there