My tool does not constantly damage the user??

As in the stated question i am trying to make my tool constantly damage the user but it only damages them once unless u rejump in the beam but as long as u stay in the beam u only get damaged once. heres the script i dont know whats the problem..

local DAMAGE = false
local db = true
function onTouched(hit)
        local human = hit
        if (human ~= nil) then
                human:TakeDamage(500)

        end
end
script.Parent.Touched:Connect(function(part)
 DAMAGE = true
script.Parent.Value = part.Parent:FindFirstChildWhichIsA("Humanoid")
end)
script.Parent.TouchEnded:Connect(function(part) 
 DAMAGE = false
end)
while true do
if DAMAGE == true then
if db == true then
        db = false
        onTouched(script.Parent.Value)
        wait (0.05)
            db = true
            end
        end
        end

please help with ur feedback, also this is just the damage script part. my tool is way bigger