Does divorce occur due to obsessive thoughts of divorce, or uttering it without the intention of divorce, or conditioning it upon returning to a foreign country without certainty?

No divorce occurs from the phrases "I took a divorce" or "she is divorced," nor from the pain your wife experienced alongside them, or from the doubt about the suspension of divorce. All of that is due to the effects of obsessive doubts (waswasa), and your wife remains under your marital bond. The cure for obsessive doubts is to disregard them.