Why is my debounce not working properly?

This script creates a fireball and launches it from your hand. It works great, but I'm having a problem with the debounce. If I press Q once and launch one fireball, the debounce waits three seconds like it should, but if I press Q multiple times, a bunch of fireballs will launch, and then wait. What am I doing wrong?

local Player = game.Players.LocalPlayer
local Mouse = Player:GetMouse()
local Debounce = true

local UIS = game:GetService("UserInputService")

UIS.InputBegan:connect(function(Key, GPE)
    if Key.KeyCode == Enum.KeyCode.Q and not GPE then
        if Debounce == true then

            local Animation = Player.Character.Humanoid:LoadAnimation(script.Animation)
            Animation:Play()

        local Part = Instance.new("Part", game.Workspace)
        Part.CFrame = Player.Character["Right Arm"].CFrame * CFrame.new(0, 0, -2) 
        Part.Anchored = true
        Part.Transparency = 1
        Part.CanCollide = false
        Part.Size = Vector3.new(0.8, 0.8, 0.2)

        Player.Character.Humanoid.WalkSpeed = 0

        local Decal = Instance.new("Decal", Part)
        Decal.Texture = "rbxassetid://301362847"
        local Decal2 = Instance.new("Decal", Part)
        Decal2.Texture = "rbxassetid://301362847"
        Decal2.Face = "Back"

        for i = 1, 11 do
            Part.Size = Part.Size + Vector3.new(0.5,0.5,0)
            wait()
        end

        local FireBall = Instance.new("Part", game.Workspace)
        FireBall.CFrame = Part.CFrame * CFrame.new(0,0,-3)
        FireBall.Transparency = 1
        FireBall.Size = Vector3.new(1.2, 2.4, 0.8)

        local Sound = Instance.new("Sound", FireBall)
        Sound.SoundId = "rbxassetid://182382770"
        Sound:Play()

        local Fire = script.ParticleEmitter:Clone()
        Fire.Parent = FireBall

        local BodyVelocity = Instance.new("BodyVelocity")
        BodyVelocity.MaxForce = Vector3.new(math.huge, math.huge, math.huge)
        BodyVelocity.Velocity = Mouse.Hit.lookVector * 80
        BodyVelocity.Parent = FireBall

        FireBall.Touched:Connect(function(hit)
            local Humanoid = hit.Parent:FindFirstChild("Humanoid")
            if Humanoid then
                Humanoid:TakeDamage(40)
                FireBall:Destroy()
            elseif
                hit.CanCollide == true then
                local Smoke = script.EvilCloud:Clone()
                Smoke.Parent = game.Workspace
                Smoke.Anchored = true
                Smoke.CFrame = hit.CFrame
                Smoke.CanCollide = false

                local Sound3 = Instance.new("Sound", hit)
                Sound3.SoundId = "rbxassetid://304529688"
                Sound3:Play()

                for i, v in pairs(hit.Parent:GetChildren()) do
                    print(v)
                    local FindFire = v:FindFirstChild("Fire")
                    if not FindFire then
                        local GiveFire = Instance.new("Fire", v)
                        GiveFire.Name = "GiveFire"
                    end
                end


                FireBall:Destroy()


                for y = 1, 40 do
                    Smoke.Mesh.Scale = Smoke.Mesh.Scale + Vector3.new(0.5,0.5,0.5)
                    wait()
                end
                wait(1)
                Smoke:Destroy()

                wait(2)
                for x, y in pairs(hit.Parent:GetChildren()) do
                    local DeleteFire = y:FindFirstChild("GiveFire")
                    if DeleteFire then
                        DeleteFire:Destroy()
                    end
                end


            end

        end)

        wait(0.70)

        for x = 1, 15 do
            Part.Size = Part.Size - Vector3.new(0.5,0.5,0.5)
            wait()

        end
        Part:Destroy()
        Player.Character.Humanoid.WalkSpeed = 16





        Debounce = false
        wait(3)
        Debounce = true
        end

    end

end)