How to add jumping and falling animation

I'm working on a platformer with a somewhat complex moveset and I've been trying to find a way to add a jump animation that ONLY plays when the first jump is triggered, as I'm also working on adding a pseudo double jump, and a falling animation that plays when the zSpd (it's a 3d platformer using the tutorial made by gamemaker to "turn a 2d game to 3d") is bigger than zero

I've attempted to add the falling animation by checking for the conditions given and then setting the current animation (I'm using a setup that sets the sprite index to a variable which is a prefix (so that I dont have to change every single name when I upload the final sprites) and a suffix which is set in the code) to the fall one and that causes jittering when the player nears ground, and attempting to add the jump animation by setting the current animation to it as long as zSpd is less than zero after/as the jump has started, but that causes the game to freeze and force me to use task manager to shut the game as closing the window doesn't work

Again I don't want to implement the jump animation by checking if the zSpd is less than zero as that's bound to make more issues as I try to add the double jump and other gimmics that affect the zSpd