unity – Learn how to pause or decelerate/pace up Time.deltaTime when it’s contained in the Replace() technique?

My participant is ready to dive for a restricted quantity of seconds (as an instance 10 seconds) whereas swimming. When he isn’t diving his breath gauge fills up once more to a max of 10 seconds:

personal bool isFreediving;
personal float breath = 10f;

void Replace()
{
    if (isFreediving)
    {
        if (breath > 0)
        {
            breath -= Time.deltaTime;
            Debug.Log(breath);
        }
        else
        {
            Debug.Log("Out of breath");
            breath = 0; // optionally available?
            isFreediving = false;
            // Do employees...
        }
    }
    else
    {
        if (breath == 0)
        {
            // TODO: Make the participant cease transferring for 1 second
            // TODO: Cease breath += Time.deltaTime for 3 seconds
        }
        else if (breath > 0 && breath < 10)
        {
            breath += Time.deltaTime; // TODO: Make breath refill slower/quicker
            Debug.Log(breath);
        }
    }
}

If the participant runs out of breath fully, I would like him to cease transferring for a second and I additionally need the breath gauge to not begin to refill for 3 seconds. I attempted with coroutines, however my code is contained in the Replace() technique, so it did not work. I notice that the above If–else statements have to be rearranged correctly.

Lastly, I would like the breath gauge to be stuffed up at a distinct tempo, for instance:

breath += Time.deltaTime * 0.5f;

I ponder if there’s a higher approach?