Sprite character slides back when near edge of other collider - unity3d

Question

I am making a 2D game in Unity. I have added a 2D box collider and a circle collider as trigger on my sprite character. The platform on which the character is standing also have a 2D box collider. So, when my character moves near edge of platform, it experiences a force or something that pulls it away from the edge. You can think it as a protective force that helps your character not falling down the plane but the problem is that this force is not part of game and that's why it should not be there. Following is the code I am using to move my character:
// call this method to move the player
void Move(float h)
{
// reduces character velocity to zero by applying force in opposite direction
if(h==0)
{
rigidBody.AddForce(new Vector2(-rigidBody.velocity.x * 20, 0.0f));
}
// controls velocity of character
if(rigidBody.velocity.x < -topSpeed || rigidBody.velocity.x > topSpeed)
{
return;
}
Vector2 movement = new Vector2 (h, 0.0f);
rigidBody.AddForce (movement * speed * Time.deltaTime);
}
Here is image of properties.
If I keep pushing the character it will fall off the edge but if I stop just by edge the unwanted protective force pulls it back on plane.
Also, if the character bumps into another 2D box collider, it bounces back instead of just falling down.
EDIT- Bouncing effect arises mostly when player bump into other objects while jumping. Code for jumping is
void Update()
{
// The player is grounded if a linecast to the groundcheck position hits anything on the ground layer.
grounded = Physics2D.Linecast(transform.position, groundCheck.position, 1 << LayerMask.NameToLayer("Ground"));
// If the jump button is pressed and the player is grounded then the player should jump.
if(Input.GetButtonDown("Jump") && grounded)
jump = true;
}
void Jump()
{
if (jump)
{
jump = false;
rigidBody.AddForce (Vector2.up * jumpSpeed * Time.deltaTime);
}
}

Answer 1

The problem lies in how you're implementing the "drag" force that slows your player down to zero. Because game physics happens in steps rather than continuously, your opposing force can overshoot and briefly cause the character to move in the opposite direction.
In this situation your best bet is to multiply your speed by some fraction each frame (likely between 0.8 and 0.95), or to use Mathf.Lerp to move your X velocity towards zero.
rigidbody.velocity += Vector2.right * rigidbody.velocity.x * -0.1f;
OR
Vector3 vel = rigidbody.velocity; //Can't modify rigidbody.velocity.x directly
vel.x = Mathf.Lerp(vel.x, 0, slowRate * Time.deltaTime);
rigidbody.velocity = vel;
Also give some thought to doing your movement/physics related code within FixedUpdate() instead of Update() and using Time.fixedDeltaTime instead of Time.deltaTime. This will allow for more consistent results independent of framerate.