Just as you said, that depends on definition. And since we know jack shit about how conciousness works all of those definitions (minus one) will be flawed. Going by some definitions that include this, you could say you die every second. I had restless nights thinking about this and the only conclusion I came to is that it’s ironically not worth losing sleep over this, because if this is true then one you can’t do anything about it two you won’t even notice it. Alternatively this is a flawed perspective and you are just overthinking something that isn’t even true.