There is too much importance put on trying to discover the one main reason your here
I don't think there is one only true purpose.
In fact this whole one purpose
thing is just silly. You're a powerful conscious being having an adventure in a physical reality, why limit yourself? You've got goals, what are they? why do they have to be linked to some kind of major reason for being here.
Get out there and have some fun, forget the need for a one single purpose, just start acting on your desires and things you find interesting. You're 25ish for godness sake, you talk like you're 98 years old and feel like you're wasted your life.
Don't be so focused on true calling, you'll get there when you start moving towards some goals, some will work, some won't, just get busy. Motivation to get out of bed isn't about wondering why you're here and why bother, you're in the game, so start interacting with it, everything's connected, you'll find a way, just get started, make mistakes, make BIG mistakes, have fun!
I used to always wonder why I was here, what was my life purpose, I couldn't figure it out. I realised all the time I was spending thinking about it, I was missing out on all sorts of cool stuff.
I still don't know why I'm really here, I think you get that real answer when you leave, but it's fun to try lots of different things along the way.