I hope you listen to what these people say. As a JW myself many years ago, I used to date non-JW girls, but never saw it going anywhere. In the back of my mind, I needed to end up married to a JW girl. And I never told my family.
Some guys think they can eventually convert you. They are brainwashed to feel so strongly about their religion, they feel that if you're a nice person too, you'll want to be a part of it.
Things have become more lax, IMO, among JWs since I left over 25 years ago, but if he is dating a non-JW girl, he might not be too serious. How active in it is he? Is he baptized? Does he do a lot of preaching? Is he serving some job function there?
Even if he isn't serious about the religion now, it doesn't mean he won't be dragged into being more serious. Better he make a break from it and be strong about it. About knowing how wrong it is and not because of you. If it's over you, he might drift back. If he knows it's wrong, it's a better chance he'll stay away. And once a JW, always a JW is NOT the case as witnessed (pardon the expression) by many, many people here.
Sometimes people proceed with relationships anyway, despite warnings. If you do, what I recommend is NEVER become one of them. If you never go and never get baptized, the rules are different. They can't "disfellowship" you if you were never baptized. Oh, they still might choose to avoid you a bit, but that's less harsh than the rules and shunning around disfellowshipping.
But the whole thing is VERY strange to me. First of all, long distance, IMO, is VERY tough to do. There's just too many distractions for both of you. And for 5 years??? Something's wrong here. Why would you keep it going? Why would he? I apologize in advance, but one or both of you has issues for trying to hold onto it this way without proceeding further. He might be only keeping a line of contact to you as a backup or as a some-of-the-time play thing. Or maybe you're insecure and feel he's the best you can get and you're holding on to whatever little bit he gives you as hope. It just sounds like some major personal issues that don't sound like the foundation for a strong marriage. And each of you should self-reflect and fix yourselves before you get into a relationship with another person that won't fix the underlying issues.