Hi Laurie! I liked your vid btw!
I completely agree with the overcoming fears part, then physical fitness. Personally, I've always been cautious, so not freaking out or overthinking things are problems I'm trying to fix. But it's such a rush when I finally do something without thinking about it, and it actually works!

Imagine that!
As for being small, I can relate. I'm no expert so I can't give you much advice on getting more height, other than maybe taking off earlier/farther away from your obstacle. Good cadence without stutter-stepping (something I have a problem with) is also important. I'm pretty sure there are some tips around here on how to increase jump height as well. Otherwise, it's a matter of finding an alternative way to get over the obstacle.
If you come across any discoveries, feel free to share. I'd love to hear them