How to cancel a trip to meet someone

So I met this guy online. He lives across the country but we really clicked (on all levels). I agreed to meet up with him in his hometown during the summer and we have talked about it since we started online dating each other. But things have happened and I’ve kinda lost feelings towards him. Nothing wrong that he did. Just life happened. I told him how I feel and he asked if we could at least keep talking over the summer. I said sure because that doesn’t seem unreasonable to me. But he asked me today if I still plan to fly out there. I don’t think I should since I want to stop dating him at the end of the summer and am not really looking to rekindle it. I let him know that I don’t really wanna date anymore and he said he understood and that we can just see each other as friends. But it’s expensive to fly all the way out there for someone who I am not dating anymore. We are talking tonight about it and I don’t know how to say it nicely. I’m very bad with this stuff. Just breaking up was a whole fiasco. Any tips with how to nicely cancel this trip on him? He really does lay it on thick when it comes to this trip. He was really looking forward to it. I am kinda sad too now but I feel like it is for the best. Any advice would be much appreciated! >.<