You sound like me. I never truly decided on one discipline. I love jumping. I love the dynamics of dressage. I love the rugged western games. I go through phases which makes it difficult for me to really chose a goal and stay focused.
I have no advice other than to be the jack of all trades but the master of none. My instructor called me that and it was right on. You gain so much more experience switching back and forth between disciplines. If you train in it all, you can do it all and become a professional. But you didn't put enough focus into one particular discilpline to be a "master" of it.
If I DID have advice, I'd say to make yourself stick with a particular discipline for at least a couple years to get a solid foundation in it before switching again. Maybe if you know more about one, you'll find a favorite.
And those who were seen dancing were thought to be insane by those who could not hear the music