When I shoot the gun I lose no health Help?

-- Script Made By johndeer2233 For A Application To Make A Game
local plr = game.Players.LocalPlayer
local Gun = script.Parent
local Ammo = 5
local MaxAmmo = 5
local AmmoGui = plr.PlayerGui:WaitForChild("Ammo")
local AmmoL = AmmoGui:WaitForChild("AmmoL")
local mouse = plr:GetMouse()
local Shot = Instance.new("Sound",script.Parent.Part)
Shot.Name = "Shot"
Shot.SoundId = "rbxassetid://131070686"

local Reload = Instance.new("Sound",script.Parent.Part)
Reload.Name = "Reload"
Reload.SoundId = "rbxassetid://317130715"
Reload.Looped = true
Reload.Volume = 10
local function shoot()
			-- Creating The Bullet
				bullet = Instance.new("Part",game.workspace)
					bullet.Shape = "Ball"
					bullet.Size = Vector3.new(0.5,0.5,0.5)
					bullet.TopSurface = "Smooth"
					bullet.BottomSurface = "Smooth"
					bullet.BrickColor = BrickColor.new("Really Black")
					bullet.CanCollide = false
					bullet.Anchored = false
					bullet.Name = "Bullet"
					--CFrame Stuff
					bullet.CFrame = Gun.Handle.CFrame 
					bullet.CFrame = CFrame.new(bullet.Position,mouse.Hit.p)
					--body velocity	
					local v = Instance.new("BodyVelocity",bullet)
					v.velocity = bullet.CFrame.lookVector * 90
					v.MaxForce = Vector3.new(math.huge,math.huge,math.huge)
					game.Debris:AddItem(bullet, 3)
					Ammo = Ammo - 1
					--Sound Management
					Shot:Play()
					local fire = Instance.new("Fire", script.Parent.Part)
					fire.Name = "Fire"
					fire.Heat = 1
					fire.Size = 2
					local smoke = Instance.new("Smoke",script.Parent.Part)
					smoke.Name = "Smoke"
					smoke.Opacity = 1
					smoke.RiseVelocity = 0.1
					smoke.Size = 0.1
					wait(1.5)
					fire:Destroy()
					smoke:Destroy()
					Shot:Stop()
	end
				-- Making Sure you lose 1 Ammo everytime you shoot.
local function reload()
		wait(1)
	repeat
		if Reload.IsPlaying == true then
			AmmoL.Text = "Ammo: "..Ammo	
			Ammo = Ammo + 1
		else
			Reload:Play()
			AmmoL.Text = "Ammo: "..Ammo	
			Ammo = Ammo + 1
		end	
		wait()
	until Ammo == 5 
	Reload:Stop()
	Ammo = 5
end
script.Parent.Equipped:connect(function()
	AmmoGui.Enabled = true
	AmmoL.Text = "Ammo: "..Ammo
	wait(1)
	AmmoL.Visible = true
	
	bullet.Touched:connect(function(hit)
			local plr = hit.Parent
			print(plr)
			local plrn = plr.Name
			print(plrn)
				if game.Players:FindFirstChild(plrn) then
					print("Stage1")
					local h = game.Players:FindFirstChild(plr).Character:FindFirstChild("Humanoid")
						if h then
							h:TakeDamage(10)
							print("Stage2")
			end
		end
	end)
end)
script.Parent.Unequipped:connect(function()
	AmmoGui.Enabled = false
	AmmoL.Visible = false
end)
script.Parent.Activated:connect(function()
	if Ammo > 0 then
		shoot()	
	elseif Ammo == 0 then
		reload()
		end
end)
while wait() do
	AmmoL.Text = "Ammo: "..Ammo
		if Ammo > MaxAmmo or Ammo < -1 then
			Ammo = 5
	end
end

no errors other then Players.Player1.Backpack.Gun.MainScript:77: attempt to index global 'bullet' (a nil value) and that is just because Bullet does not exist until you shoot. Help?