you have to realize that your fear of heights is going to hurt you way more than the height itself.  like if youre scared of the height on a jump, you will naturally slow down.  but when you slow down, you dont have enough speed to clear the jump, so you will get hurt.  just think about that before you approach the jump, so you get the confidence to have enough speed to clear the jump.  then, once you clear the jump, you will probably think to yourself how scary it was.  this is okay because just going straight off a jump makes it seem alot scarier than if you do something off of it. so then once you clear it, try something (even if its only a grab) because it helps you take your mind off of the heights, and makes you focus on the trick youre doing.