WebGL mesh not working when I add things to mesh

I’m making a 3D physics engine and I need to add balls when I press a button, but whenever I click it, everything goes blank.

Here’s the code for the loop, event, and Ball object.
Loop: Cleares mesh, does physics and draws, solves collisions, updates mesh, and finally draws it.

initGL()
function loop(){
    //clear to animate
    
    mesh.verts=[
    ]
    mesh.inds=[]

    mesh.ind=0
    //do physics math
    balls.forEach(ball => {
        //draw sphere
        ball.draw()
        ball.phys()
    })
    //collisions
    for (let i = 0; i < substeps; i++){
        balls.forEach(ball => {
            ball.collwall()
            ball.collballs()
        })
    }
    //update the WebGL vertex array buffer and index array buffer
    mesh.update()
    runGLFrame()
    
    requestAnimationFrame(loop)
}
requestAnimationFrame(loop)

Event: Adds ball, updates mesh, clear mesh, draw all balls, updates mesh.

    balls.push(new Ball(5,5,0,0,0,0,1,0,1,1,1,0.8)) 
    //update the WebGL vertex array buffer and index array buffer
    mesh.update()
    //clear to animate
    mesh.verts=[
    ]
    mesh.inds=[]

    mesh.ind=0
    balls.forEach(ball => {
        ball.draw()
    })
    mesh.update()

Ball constructor: Initializes the ball object and draws a sphere.

constructor(x,y,z,vx,vy,vz,rad,r,g,b,w,bons){
    //sphere number
        this.sn=balls.length
        //current pos.
        this.p={x,y,z}
        //past pos.
        this.pp={x:x-vx,y:y-vy,z:z-vz}
        //velocity
        this.v={x:vx,y:vy,z:vz}
        //weight
        this.w=w
        //bounciness
        this.b=bons
        //radius
        this.rad=rad
        //color
        this.c={r,g,b}
        //add sphere to mesh, vertices and indices
        mesh.addSphere(20,20,x,y,z,rad,r,g,b)
   }

It was supposed to create a ball at 0,5,0, but instead it cleared everything. I copied the clear mesh code to the event to try to copy the thing that happens when I initialize it (before the loop and event) but it still doesn't work.