Wait 3 seconds for an unchanged value, then gradually increase until its decreased again?

Im working on making a stamina script where it always checks (in a span of 3 seconds) if the stamina has changed or not. If it hasnt, then it will gradually increase until it detects it is decreased again.

Here is my script:

while wait(.167) do
if c:FindFirstChild("Stamina") then
	local stamina = c:FindFirstChild("Stamina").Value
	spawn(function()
	delay(3,function ()
		if c:FindFirstChild("Stamina").Value == stamina and stamre == false then
			stamre = true
		else
			stamre = false
		end
	end)
	end)
	if stamre == true then
		c.Stamina.Value = c.Stamina.Value + 1
	end
end
end

And it isnt working too well. Can someone help fix it up for me? Thanks

local staminaValue = --Put value here

function Increase()
	--Code to increase stamina over 3 seconds here
end

lastStam = 0
while wait(3) do
	if staminaValue.Value >= lastStam then
		Increase()
	end
	lastStam = staminaValue
end

Short and simple. It checks if the stamina is going down every 3 seconds and if it's not then it will increase. If it is then it won't do anything. Comment if you need further assistance.