How do you make an if statement end the script if a condition is met?

You would use a break statement, search it on the wiki for more information.

Here's an example, we will be using a BoolValue for this example that has just been changed to true. The script is a child of Boolvalue

script.Parent.Changed:connect(function() -- This just detects a change in a bools value, it does not need to be added.
    if script.Parent.Value == true then -- Replace "script.Parent.Value == true" with your statement.
        print("Condition met") -- Ends the script with a print.
    else
        print("Condition not met") -- If you want to put some code here if the bool does not meet the requirements then do.
    end
end)