I think when he says lose a friend he means the friend died and if so, I'm sorry for your loss.
As for with your girlfriend, LDR's are always gonna be hard. It takes a lot to make them last. You have to put in the effort and try not to let the little things get in between you two.
I personally can not see myself doing one again unless it is continuing an already growing relationship with someone I've been with and they had to go away for school or whatever(Sadly even then it might not happen but that is the only time I would consider it).
Do you love this girl? Do you think being in an LDR is worth it with her? How often do you guys meet?
..::.*Love is giving someone the ability to break your heart but trusting them not to*.::..