Making a melee combo script, but it returns to no combos after one attack?

if Input.UserInputType == Enum.UserInputType.MouseButton1 then
			if Combos == 0 then
				Combos = Combos + 1
				Swing1:Play()
				Attack:FireServer(Character)
				local BV = Instance.new("BodyVelocity", Character.HumanoidRootPart)
				BV.MaxForce = Vector3.new(math.huge, math.huge, math.huge)
				BV.Velocity = Character.HumanoidRootPart.CFrame.lookVector
				Debounce = true
				wait(Wait1)
				BV:Destroy()
				Debounce = false --Add STR
			elseif Combos == 1 then
				Combos = Combos + 1
				Swing2:Play()
				Attack:FireServer(Character)
				local BV = Instance.new("BodyVelocity", Character.HumanoidRootPart)
				BV.MaxForce = Vector3.new(math.huge, math.huge, math.huge)
				BV.Velocity = Character.HumanoidRootPart.CFrame.lookVector
				Debounce = true
				wait(Wait2)
				BV:Destroy()
				Debounce = false
			elseif Combos == 2 then
				Combos = Combos + 1
				Swing3:Play()
				Attack:FireServer(Character)
				local BV = Instance.new("BodyVelocity", Character.HumanoidRootPart)
				BV.MaxForce = Vector3.new(math.huge, math.huge, math.huge)
				BV.Velocity = Character.HumanoidRootPart.CFrame.lookVector
				Debounce = true
				wait(Wait3)
				BV:Destroy()
				Debounce = false
			end
			wait(0.5)
			Combos = 0

Whenever I try and attack once, it just simply returns me to 0 combos and doesn't play out there rest of the script. How do I fix this?