How to solve Jump Problem?

[Sourav.Sutradhar]

I want my player to jump. In OVRPlayerController.cs, I commented out the following code.

if (!Controller.isGrounded)
MoveScale = MoveScaleFloatValue;

After that I set my Gravity Modifier to 0.1, and I called the jump function from a different script using 

if (OVRInput.GetDown(OVRInput.Button.One))
{
gameObject.GetComponent<OVRPlayerController>().Jump();
}

Now my player jumps, but it is not smooth. The player falls down too fast. And If I try to move while jumping, my player moves too fast. Maybe 10 times faster than when I am walking. How to solve these two problem. Mostly the second problem. Can anyone help me? I am stuck in this problem for nearly 4 days.

Thank You.