Well, first, in your question, the correct word is "ambas" and not "ambos".
Then, I would say "Estaba reflexionando sobre mi experiencia", I wouldn't use "reflexionando de".
Then, to your question, I would say "tuve" and not "tenía".
Last but not least, if the meaning of the phrase is "I didn't have the chance to say good-bye." I would say it like this "No tuve la oportunidad de despedirme de tí." or you could say "No tuve la oportunidad de despedirte." I still would use the first one, though, because even though the second one is correct and people would understand the context, in Spanish, especially in Latin America, "despedirte" sounds more like "firing someone from their jobs" (which is another meaning of "despedir"). We tend to use "despedir" in the reflexive form, that is, "despedirse" and you use the preposition "de" with that verb, e.g. "Me tengo que despedir de ella antes de partir."