Help with hovering/flying?

Im working on a game where there are these boxes that you can spawn in, you are supposed to control it with your mouse. But some times they get very laggy. Please help.

debounce = false
player = game.Players.LocalPlayer
b = Instance.new("BodyVelocity")
b.MaxForce = Vector3.new(math.huge,math.huge,math.huge)
b.Velocity = Vector3.new(0,0,0)
mouse = player:GetMouse()
house = script.Parent
b.Parent = house
moving = false
function Talk(msg)
	game:GetService("Chat"):Chat(house, player.Name..": "..msg, Enum.ChatColor.Red)
end

function Aim()
	if debounce == false then
	debounce = true
	
	local aimer = Instance.new("Part")
	aimer.Transparency = 0
	aimer.Anchored = true
	aimer.CanCollide = false
	aimer.Parent = game.Workspace
	aimer.CFrame = mouse.Hit
	house.CFrame = CFrame.new(house.Position, aimer.Position)
	aimer:Destroy()
	
	if moving == true then
		b.Velocity = Vector3.new(0,0,0)
	b.Velocity = house.CFrame.lookVector*20
	end
	wait(.1)
	debounce = false
	end
end

mouse.Move:connect(Aim)
mouse.Button1Down:connect(function()
	moving = true
	b.Velocity = house.CFrame.lookVector*20
	mouse.Button1Up:connect(function()
		moving = false
		b.Velocity = Vector3.new(0,0,0)
	end)
end)

player.Chatted:connect(Talk)