I've literally just finished a post that's about this very subject! Not sure when it will be published, but perhaps it will have some food for thought which could help you through your process. Regardless of your choice, it's not easy. But your growth and revelations outside of your friendship are worth honoring. I've exprienced this many times, both with friendships, family members, and romantic partners. I'm not proud to say that I usually let it fizzle and dissipate without explanation. Sometimes that feels like the right choice, but other times it feels like clarity would be best. If only we had a manual for such situations, then all would be revealed. Best of luck in your dilemma and I hope that you continue to enjoy living abroad.