Ooohh boy! Do I love the destiny conversation! Because it always boils down to being forced into a choice between believing in free-will or believing in pre-destination... as if there is no middle ground. So here is my take. This is my opinion based on my experience. Take what suits you, leave the rest.
Destiny takes the form of one's passions, enthusiasms and burning desires. Those things that you have been thinking about since you were a kid and still get your wheels turning. Those things are your destiny, those things are what you are SUPPOSED to be focusing on! Why else do you think that they resonate within you so intensely? You are supposed to follow that passion! When you do not, your light goes down, food loses flavor, exuberance fades, you are not doing what you are supposed to be doing and the Universe shows you that by removing the color from your life. It will literally put you in more and more pain until you you realign yourself with your passions, with your purpose, with your destiny.
But, what of free-will?
You, have all the free will of a fish swimming in a broad and mighty river. You are free to go anywhere in that river that you like. Some places in that river are safe, some places in that river are dangerous, but both are equally available to you. You can hang out in the calm, still water, but it will not offer much experience or reward. You can hang out in the turbulent rapids, but eventually you will get tired of getting your ass beaten. You can swim upstream, or downstream, you can travel fast with the current or grow strong by fighting against it. The one thing that you cannot do is get out and take a walk in the woods, you are a fish and that option is not available to you, regardless of how much free-will you believe you have.
In the end, you have 2 choices, and they are entirely yours to make. Where the river is going is your destiny. You can spend your life denying it, swimming against the current, hiding behind rocks, defying the pull of what you were born to be. It will eventually drain you of your energy and you will die having never seen, felt, or experienced your destiny. Or you can embrace it, seek it gleefully, feel yourself moving effortlessly in the flow, give in to the current and feel how gracefully it flows around large rocks and obstacles, instinctively finds pathways through that otherwise appear to be blocked.
You have a destiny brother, you've felt its pull since you were a child. Your free-will will determine whether you embrace it or not.