It is my personal view that things are meant to be easy in this life. And that if they are difficult it is because 'we' meaning ourselves, make it more complicated.
So in light of that fact your purpose is what you desire most, what you enjoy doing the most.
I want to make a distinction here between need, want and desire.
Need = those things we think we cannot live without – fear based
Want = those things we don't want to live without – ego mind based
Desire = that which the universe wants us to have – spiritual based
So that which you truly desire, that which you love to do, that thing that you just really love, that to me is your purpose in life.
Now here is the real shocker.
Your purpose in life can change. You may not always have the same purpose.
How do you know if your purpose changes? Because what you love to do changes. To me it is that simple.
The universe made it really easy for us to find our purpose and do it. She made it the most enjoyable thing we do. How great is that.
If you believe it is more complicated than that, then you are right it is, for you.
And if you want to believe it is this easy, it is. So congratulations, now you just have to muster up the courage/love to actually follow your passion, your life purpose. It may not be easy, but it sure is simple. Just do it.