My boyfriend want to leave

My boyfriend wants to work internationally, basically out of state from where we live. I want him to have great opportunities and to take them, but it makes me sad that he will leave us behind. I told him I couldnt do long distance (not out of manipulation, but genuinely that I wont-be able to keep our relationship) and he told me that I was reaching, we won’t know if he’s going to leave yet.

Anyway, I don’t know how to feel, I’m happy that he can go places in his life, but sad that I won’t be apart of the journey...

How do I deal with this?