Oh young one....
You cannot possible lose him because you do not "have" him. He is manipulating you and you are beginning to fall for it. There is no love here, just an internet hook up. He has been conditioning you to send him photos and once you do that, they are OUT IN THE WORLD for anyone to see. You never even met this guy in person and you ONLY know what he wants you to believe. I realize you are young and very naive, I get it and it is very evident because you are actually considering this hogwash idea of taking naked photos of yourself and sending them to him. That has got to be the most foolish thought you have ever had. And, yes, trust me, you will regret it. Once those photos leave your possession, there is NO telling what will happen to them and who will see them. Your parents, your friends, your enemies, your boss, a college professor and anyone else can potentially see your nude photos.
Meeting up with him for sex in two months is LAUGHABLE. How could you be so freaking stupid? You are not going to have that "special" time like you think. He told you it is not special. YOU are NOT special to him because if you were, he would NEVER ask you to expose your nude body like he is asking you to do.
But, teenagers think that they are really smart and know it all, so do what you are going to do and then let the chips fall where they land and be prepared for the consequences of your ridiculous actions. The nude photos are a dumb idea and meeting up with a guy for sex has got to be the dumbest thing you can do. But, you are a teenager and you know it all, so have your self a merry little time while you put your reputation on the line for some guy who wants to hook up for sex and then dump you.
You need to grow the hell up. Do you even KNOW what an open relationship actually is? It means he has multiple sex partners and is telling you so. You are not all that special to him. There are girls just like you who he is hooking up with right now. You are just one of many of the girls he has lined up to f+ck. Wake up.