Your only 20 man, no need to feel depressed as it sounds to me once you have narrowed down what you want to do you will actually be good at it. I'm similar to you as I am a jack of all trades, master of none. This is a good attribute in many management roles. I think you should go to uni, its a great experience and you will mature a lot over the three years and make many new friends. Then once you graduate you should go for that job.
Thats just my opinion of your situation. My older brother did sports and exercise science BSc level and is now looking at becoming a General Manager at fitness first.