blindsided breakup

Tonight my boyfriend of 6 months broke up with me over FaceTime and I was completely blindsided. We have been long distance (3 hour drive) for 4 months and see each other almost every other weekend. The time we do spend together is amazing and we had talked about a future together. We made sure to talk to each other every day that we weren’t together. Then tonight he FaceTimes me out of nowhere and says that a LDR is more difficult than he anticipated and we should break up. I am just so confused. He said he still really likes me and he has never mentioned how difficult long distance is for him before so I am just so confused. Does it sound like something else is going on? Or do you think it really is just the distance that is the issue?