Is there a way to fix this punch script I made?

I made a basic punch script but there is a problem. I made a local script in starterpack and made a keydown function,when you press e your arms move and and it makes a punch noise after that it executes this script below which deals the damage, the problem is When a humanoid touches the left arm it automatically does damage when I don't press "e" any help?

local debounce = false

function onDamage(Part)
    if not debounce then
        debounce = true
    if Part.Parent:FindFirstChild("Humanoid")~= nil and Part.Parent.Name ~= "script.Parent.Name" then 
         script.Parent.hit:Play()

            Part.Parent.Humanoid.Health = Part.Parent.Humanoid.Health -1.4
            wait(1)
            debounce = false
        end
    end
end

script.Parent.Parent.Parent.Character["Left Arm"].Touched:connect(onDamage)