What's the hard things about long distance relationship? I said i'm okey, but when he leaves i started to cry.

i did not get into one before, so am not sure if i can advice u, and also idk if he left for long or short time, but anyway; just be the person who makes him forget about his issues, and try to support him, mutually he has to be good with you as well, be strong and satisfied about ur situation from God, this is the best for u both, even if it doesn’t appear like that.
Kelkit Grdk also answered this question with: "Dont"