Methods to progressively overcome a fear of heights?

As the title implies, I have a fear of heights and am looking for ways or methods to overcome this fear.
I used to practice a little bit of parkour years ago. After a while, things began going downhill for me so parkour was an on and off thing until I stopped it completely.
Things for me are now a bit more stable and heading in the right direction, ergo I would definitely enjoy beginning parkour practice again, but there’s one thing : Heights.
Now, with this mental obstacle, it’s odd how I manage it. I have a fear of heights, yet there are some times more than others when I would proceed to climb high objects and even jump off of them. So, do I have a genuine fear of heights, or is it all sort of an illusion?
And if so, I would like some ways to progressively overcome this supposed fear.

Thank you for your time and responses, they are greatly appreciated.