how do i make a working Keybinding animation script?

Hello, so here is the script that i made, after you press R it should play animation when you have your arms crossed, until you press R again to stop the animation. But instead it started playing the animation, and even if i pressed R again it didnt stop. i tried putting print "case a" and print "case b" to both if functions, and in output when i pressed R it only showed me case a, basically the first "if". Also, can the reason be that my animation is looped?(also i already tried writing anim:Stop() instead of anim:Destroy(), it still didnt help). Thank you all in advance.

Player = game.Players.LocalPlayer
mouse = Player:GetMouse()
local anim = nil
--Put me in StarterGui
mouse.KeyDown:connect(function(key)
key = key:lower()
	if key == "r" then
		anim = Player.Character.Humanoid:LoadAnimation(script.TestAnim)
		anim:Play()
	elseif key == "r" then
		if anim ~= nil then
			anim:Destroy()
		end
	end
end)

Hello, I have an error "Humanoid is not a valid member of the model"

Player = game.Players.LocalPlayer
local Character = Player.Character
local Humanoid = Character.Humanoid
local animID ='rbxassetid://5161042536' 
local UIS = game:GetService("UserInputService")
local db=true

UIS.InputBegan:Connect(function(input)
    if input.KeyCode == Enum.KeyCode.E and db == true then
		  local Animation = Instance.new("Animation")
		Animation.animID = animID
		local LoadAnimation = Humanoid:LoadAnimation(Animation)
	
	LoadAnimation:Play()
	else
		db = true
		print("F")

    end

end)