I have 2 problems with my air meter GUI script?

My GUI is an air meter. When entering a giant no-cancollide part, a giant air bar frame shows up and goes to the left. When the blue part of it reaches the end, the player takes damage over time. If you get out, your air instantly refills and disappears. However, when the player is mid-drowning and you get out, you still take damage, and if you get back in the air still shows as 0. I can't UDim2 because TweenSize will not work anymore.

So, I need help with stopping the player from taking damage if they get out, and refilling the air meter if the player goes back in by somehow ending the TweenSize operation mid-way. Perhaps break?

local air = script.Parent
local hitbox = game.Workspace.WaterHitbox
local airBar = air.CurrentAir
local drowning = false
local touching = false
air.Enabled = false

hitbox.Touched:connect(function(part)
    local touching = true
    local humanoid = part.Parent:FindFirstChild("Humanoid") 
    if (humanoid ~= nil) then   --if a humanoid exists
        air.Enabled = true --show air bar
        airBar:TweenSize(UDim2.new(0, 0, 0, 70), "Out", "Quad", 10)
        if airBar.Size.X.Offset == 0 then
            drowning = true
            repeat
                humanoid.Health = humanoid.Health - 0.5
                wait(0.25)
            until drowning == false and touching == false
        end     
    end 
end)

hitbox.TouchEnded:connect(function(part)
    touching = false
    local humanoid = part.Parent:FindFirstChild("Humanoid")
    drowning = false
    if (humanoid ~= nil) then
        if not airBar.Size == "{0, 544},{0, 70}" then
            airBar:TweenSize(UDim2.new(0, 544, 0, 70), "Out", "Quad", 3)
            air.Enabled = true
        else
            air.Enabled = false
        end
    end
end)