Desire & Destiny

Desire is something that one wants - it is something that is wished upon. A desire is a want but not always is it a need but it is a wish.
Desire can also be a dream which one wants to make into reality.
What you desire is not always what you will get. But only if you desire is it possible for you to get something. A desire can be a goal we set for ourselves and only after we desire it can we achieve it. However, there can be a case where you might not desire something but you are destined for it.
Eg: you might not desire a job change but your destiny would take you to another job which can either be for the better or not.

Some say that destiny is already written for us; its fate. And some say that we create our own destiny. Can destiny change? Is it self made? People say that everything happens for a reason - is that destiny? If destiny is manmade, why is it that certain things happen for a reason as we are the ones creating it. Destiny is not something of the past, it is about the future.
I am unsure as to whether destiny is written or self made.

Destiny is the end goal, it is the end destination. But is it so? Is destiny something like karma? Or is destiny effected by karma? Is destiny defined by our karma? Depending on our karma, we are destined to certain things in this lifetime and so on. Just like how we have good karma and bad karma, does that weave our destiny?

If destiny is not manmade, is it fate? Can desire turn into destiny?