How do I get block to move in one direction until another movement key (wasd) is pressed?

So basically, I'm trying to make a snake game and I want the snake to move in the direction of the button you pressed until you hit another key. I tried using repeat but it crashed my game so I'm not really sure where to go for there any help? My code is below ty :D

local board = game.Workspace.SnakeGame
local start = game.Workspace.Start
local clickdec = start.ClickDetector
local UIA = game:GetService("UserInputService")
local head = Instance.new("Part")

clickdec.MouseClick:Connect(function(touch)
    head.Parent = workspace
    head.Position = Vector3.new(-47.935, 23.075, -57.975)
    head.Size = Vector3.new(2.39, 2.31, 0.05)
    head.BrickColor = BrickColor.new("Gold")
    head.Anchored = true

end)

UIA.InputBegan:Connect(function(touch)
    if touch.KeyCode == Enum.KeyCode.Space
        then head.Parent = game.ServerStorage
        end

    repeat
    if touch.KeyCode == Enum.KeyCode.W
        then head.Position = head.Position + Vector3.new(0, 1,0)
        end
        if touch.KeyCode == Enum.KeyCode.S
        then head.Position = head.Position + Vector3.new(0, -1,0)
        end 
        if touch.KeyCode == Enum.KeyCode.D
        then head.Position = head.Position + Vector3.new(1, 0,0)
        end 
        if touch.KeyCode == Enum.KeyCode.A
        then head.Position = head.Position + Vector3.new(-1, 0,0)
        end
    until UIA.TouchEnded    


end)