This is a wrong question that cannot originally be asked as a correct one. Can I ask a question? Can God cease to exist? Absolutely not, this is a contradiction, it is like asking how many days are in a week? Yes or no? It is not a yes or no question, how many days are in a week? Seven. So your question is wrong in itself, so to ask can God create a rock of this size and not lift it? This means that the moment he created this rock he became weak (unstrong) because he could not carry it and there is no such thing, as this is a question that does not make sense.
These questions that pertain to God's creation, such as: Can God create a rock that He cannot lift? Can God cease to exist? These questions cannot be asked because they are corrupt questions.