My Mommy Fear

I have never had a fear of heights that I can remember. So the only thing I can contribute to this feeling I experience is my children.
Does it ever happen to you?
That feeling where your stomach feels like it is in your throat?
Or you feel your heart beating so hard it might actually explode?
My latest experience was last night on an escalator. You read that right...an escalator!
OM is our little adventurous soul. He'll leap off of the stairs or bed without us knowing what he's doing. He expects us to catch him. Or it's "Look mom, I can fly like Batman!".
Back to the ever frightening escalator. He wants to get on by himself which is fine until I step on and he doesn't! I reach back in time to get his outstretched hand and he jumps on. Whew! I hold that little hand tight because he could fall backwards and die.
Yes, everything with heights involved in my head ends up with one of my children being seriously injured or dead! Please tell me I am not the only mom?! Please!!
We had gone to the mall to buy him some new shoes since the ones he loves have holes in the toes. This was our "fun" thing to do before heading out. Up one side and down the other.
Up not so bad because I have the death grip on his hand but down?!
"I can do it myself" I hear. My heart starts beating fast and the stomach in the throat thing happens. I mean he's 4 now but oh my goodness. My mommy head starts spinning that he will step on and slip and fall down and die!
I pull it together and let go of his hand. Standing next to him making sure he steps on right with me. And guess what he did it! I know he is more than capable but sometimes the fear grips me.
We made it to the bottom with no hand holding and about 5 steps from the bottom he "leaps" off.
My boy will be a boy and have no fear and this momma needs to get a grip!
Another place I get this feeling is the playground. Why?? Not like they are up miles high but for some reason again they will fall and die!
Okay, so I know that is a bit dramatic but it's how my brain works. I know that broken bones are in our future at some point and I do not want them to be fearful. SK has already had about 7 stitches under her left eye when she was about 2. I want them to climb trees and swing on vines over the creek like I did growing up. Just don't know how to tame it. Maybe I shouldn't. ?
Does your mommy brain ever kid in like mine with a similar fear?