I think that if you, OP, have been having these feelings for a long time, and maybe kind of stuffing them down because you feel you should NOT have them, then they are probably correct. Meaning, your soul is trying to tell you that it needs more than riding. It is out of balance, and even at the young age of 13, and you strike me as a mature 13 year old, your soul knows when there is not enough balance in your life.
I am not sure if you need to fully sever yourself from horses in order to feel free enough to take up another sport/hobby. Some may say, just cut downthe amount of time you spend on horses, and that may be possible, but it might require that you DO completely cease horses for awhile. If you own a horse (did you say you did?), then that is not possible.
But riding because you HAVE to, or becuase you are so good at it that it would be a waste not to ride, doesn't sound like it's fulfilling at this time.
You are so young that you could take 10 years off , come back to riding, and still become a champion rider is you so desired.
In my fantasy, I think I would have loved a childhood like yours, but , hearing you talk about it makes me think again. maybe not.