In my experience, you can't find your life's purpose, you can only make one. There isn't any thing external or even internal that defines what your one true purpose is. You just choose it, and keep choosing it. And maybe later you choose something else. Life (in my own understanding) has no meaning except that which we decide to give it* - and to me that's the best thing about it.
The point here is that I don't have a Purpose as in some divine being put me on this planet to do some specific thing. The only purpose of my life is to LIVE it. The only purpose of my being is to BE it. To do that, I have to know what the heck it is in the first place. But there's not One True Answer for what my life is supposed to be or look like. I have to design it for myself because there is no grand design. It's a lot of responsibility, but the good thing is that there's no real messing it up. You just try, have some setbacks, make some mistakes, get off track, rethink the design, try again, and as long as that's what you're expecting, you can really enjoy yourself along the way, even during failed iterations.