UserinputService does not work properly, any solutions ?

So, basically this script was supposed to work i assume, the script should've run something every time i hold my mouse's left button and then stop when i release it, but instead when i click once it just runs without stopping, but if you hold it a little longer, it works fine, i don't understand why isn't it working, i hope you can help me.

tool.Equipped:Connect(function()
	game.ReplicatedStorage.Equip:FireServer()
	mouse.Icon = "http://www.roblox.com/asset/?id=79658449"
	TextLabel.Visible = true

	UIS.InputBegan:Connect(function(input)
		if input.UserInputType == Enum.UserInputType.MouseButton1 then 
			pressed = true  
			while pressed and tool.Equipped do			
				if Ammo1 <= 0 then
					pressed = false
				else
					Ammo1 = Ammo1 - 1
					tool.GunShot:Play()
					if mouse.Target.Parent:FindFirstChild("Humanoid") then
						script.Parent.Damage:FireServer(mouse.Target)
						tool.Enabled = false
						print("target hit")
						wait(0.09)
						tool.Enabled = true		
					else 
						tool.Enabled = false
						print("miss")
						wait(0.09)
						tool.Enabled = true
						
	UIS.InputEnded:Connect(function(input)
		if input.UserInputType == Enum.UserInputType.MouseButton1 then  
			pressed = false