Status Negating script breaks after humanoid death can't figure out why?

Local Script located in StarterPlayerScripts. Throws the error "Nutrition is not a valid member of Frame" which occurs at line 47. Here is the hierarchy of the gui http://gyazo.com/38c20af365389ff1a06c31a08f2328cb

--Establish variables
---------------------------------------------------
local player = game.Players.LocalPlayer
local playerGUI = player.PlayerGui:WaitForChild("PlayerStatus")
local mainFrame = playerGUI:WaitForChild("Frame")
local nutrition = mainFrame.Nutrition.Size.X.Offset
local hydration = mainFrame.Hydration.Size.X.Offset
local nurture = mainFrame.Nurture.Size.X.Offset
local originalNurture = nurture
local originalHydration = hydration
local originalNutrition = nutrition
local debounce = false
local debounceN = false
local debounceH = false
local debounceHealthLoss = true
local lnValue = 2
local lhValue = 3
local statusNegateWait = 1/100
local lhealthValue = 3
--Functions
---------------------------------------------------
function lowerHealth(v)
    if nurture < v then
        mainFrame.Nurture.Size = mainFrame.Nurture.Size-UDim2.new(0,nurture,0,0)
        nurture = 0
        mainFrame.Nurture.TextBox.Text = "Nurture: "..(math.floor(nurture/originalNurture*100)).."%"
        wait(statusNegateWait)
        player.Character.Humanoid.Health = 0
    else
        nurture = nurture-v
        mainFrame.Nurture.Size = mainFrame.Nurture.Size-UDim2.new(0,v,0,0)
        mainFrame.Nurture.TextBox.Text = "Nurture: "..(math.floor(nurture/originalNurture*100)).."%"
    end
end
function lowerNutrition(v)
    if nutrition <= v then
        debounceN = true
        if debounceHealthLoss == true then
            statusNegateWait = 1/10
            debounceHealthLoss = false
        end
        mainFrame.Nutrition.Size = mainFrame.Nutrition.Size-UDim2.new(0,nutrition,0,0)
        nutrition = 0
        mainFrame.Nutrition.TextBox.Text = "Nutrition: "..(math.floor(nutrition/originalNutrition*100)).."%"
    else
        nutrition = nutrition-v
        mainFrame.Nutrition.Size = mainFrame.Nutrition.Size-UDim2.new(0,lnValue,0,0)
        mainFrame.Nutrition.TextBox.Text = "Nutrition: "..(math.floor(nutrition/originalNutrition*100)).."%"
    end
end
function lowerHydration(v)
    if hydration <= v then
        debounceH = true
        if debounceHealthLoss == true then
            statusNegateWait = 1/10
            debounceHealthLoss = false
        end
        mainFrame.Hydration.Size = UDim2.new(0,0,0,20)
        hydration = 0
        mainFrame.Hydration.TextBox.Text = "Hydration: "..(math.floor(hydration/originalHydration*100)).."%"
    else
        hydration = hydration-v
        mainFrame.Hydration.Size = mainFrame.Hydration.Size-UDim2.new(0,lhValue,0,0)
        mainFrame.Hydration.TextBox.Text = "Hydration: "..(math.floor(hydration/originalHydration*100)).."%"
    end
end
while debounce == false do
    if debounceN == false then
        lowerNutrition(lnValue)
    end
    if debounceH == false then
        lowerHydration(lhValue)
    end
    if debounceHealthLoss == true then
        if hydration < 50 or nutrition < 50 then
            lowerHealth(lhealthValue)
        end
    else
        lowerHealth(20)
    end
    wait(statusNegateWait)
end