Problem with implementing a dash mechanic in platformer (2d)

Questions & Answers
1

Okay, so I want to dash a certain length if I press a button, yadda yadda yadda. However, when my code is in ONLY Update(), the length that I dash is inconsistent. If I swap Update() with FixedUpdate(), my button presses dont register half the time. Is there any way to fix this? I have been on it for days.

(Btw im a noob with my first game so please go easy on me!)

Here is my dash script:

using System.Collections;
using System.Collections.Generic;
using UnityEngine;

public class Dash : MonoBehaviour
{

    private Rigidbody2D rb;
    public float dashSpeed;
    private float dashTime;
    public float startDashTime;
    private int direction;

    void Start()
    {
        rb = GetComponent<Rigidbody2D>();
        dashTime = startDashTime;
    }

    // How would I fix this?
    void FixedUpdate()
    {

        if (direction == 0)
        {
            if (Input.GetKeyDown(KeyCode.C))
            {
                direction = 1;
            }
            else if (Input.GetKeyDown(KeyCode.V))
            {
                direction = 2;
            }
        }
        else
        {
            if (dashTime <= 0)
            {
                direction = 0;
                dashTime = startDashTime;
                rb.velocity = Vector2.zero;
            }
            else
            {
                dashTime -= Time.deltaTime;
                if (direction == 1)
                {
                    rb.velocity = Vector2.left * dashSpeed;
                }
                else if (direction == 2)
                {
                    rb.velocity = Vector2.right * dashSpeed;
                }
            }
        }
    }
}
2

Yes, the proper way is to split the code up, you get the input in Update() and apply the physics in FixedUpdate() or you could try multiplying by deltaTime: rb.velocity = Vector2.left * dashSpeed*Time.deltaTime;