Why does my script activate when I press Space multiple times instead of one?

Hey. I want to make a script that makes the player fall slower when they're at least 300 studs above the ground and have pressed Space. I wrote the script but for some reason it doesn't activate unless I press Space multiple times after I've began falling. And it takes a long time to activate. Any help?

Script:

local UserInputService = game:GetService("UserInputService")

local player = game.Players.LocalPlayer

local char = player.Character

local Hum = char:WaitForChild("Humanoid")

local Look = script.Parent:WaitForChild("HumanoidRootPart")

local GlideThing = script:WaitForChild("GlideThing")

local Speed = Hum.WalkSpeed

local HumanoidState = nil

local canGlide = false

local gliding = false

local KeyPressed = false

Hum:ChangeState(Enum.HumanoidStateType.Jumping)

Hum.StateChanged:Connect(function()
	local State = Hum:GetState()
	if State == Enum.HumanoidStateType.Freefall then
		HumanoidState = "FreeFall"
	else
		HumanoidState = nil
	end
end)

function Check()
	if HumanoidState == "FreeFall" then
		local ray = Ray.new(Look.CFrame.p, Look.CFrame.UpVector * -300)
		local part, position = workspace:FindPartOnRay(ray, char, false, true)
		if part then
			canGlide = true
		else
			canGlide = false
		end
	else
		canGlide = false
	end
end

function Check2()
	local State = Hum:GetState()
	if State == Enum.HumanoidStateType.Landed then
		canGlide = false
	end
end

Hum.StateChanged:Connect(function(OldState, NewState)
	if NewState == Enum.HumanoidStateType.Running then
		canGlide = false
		GlideThing.Parent = script
	end
end)

Hum.StateChanged:Connect(function(OldState, NewState)
	if NewState == Enum.HumanoidStateType.Landed then
		canGlide = false
		GlideThing.Parent = script
	end
end)

function Glide()
	Check()
	if canGlide == true then
		wait(.3)
		Check2()
		if canGlide == true and KeyPressed == true then
			if gliding == false then
				gliding = true
				Speed = Hum.WalkSpeed
				Hum.WalkSpeed = 50
				GlideThing.Parent = char:WaitForChild("Head")
				KeyPressed = false
			end
		end
	else
		if gliding == true then
			gliding = false
			Hum.WalkSpeed = Speed
			KeyPressed = false
			if GlideThing.Parent ~= script then
				GlideThing.Parent = script
			end
		end
	end
end

UserInputService.InputBegan:Connect(function(input)
	if input.KeyCode == Enum.KeyCode.Space then
		KeyPressed = true
		Glide()
	end
end)