Long-distance relationships can be hard due to a handful of things, but the core problem of it all is actually the fact that you are far apart. Every single problem is actually caused by that. You are afraid they are going to cheat on you or meet somebody else they love more than you. You think they are going to forget you or simply ghost you one day. You think you are going to grow apart. All that is due to the fact that you are far, because, in reality, that could happen even if you were neighbors. A relationship can end because of many factors, but distance may be one of the most important contenders.
I have never been in a long-distance relationship myself, but I have several friends who did. Getting to watch them fall in love with somebody they have never met in real life, then start dating even though they have never been in the same place, and after a while get to finally meet each other is really wholesome. Especially the times when it ended with a happy ending. I remember that a high school friend of mine started dating a guy that he met through a video game chat. At first it was all pretty weird and complicated because they had never met in real life, but they knew everything about each other because of their chats. One day this guy told my friend that he was coming to our town to visit him. He did, and they met. Everything went so well between the two that they decided to start visiting each other more frequently. Nowadays, they live together. All because they were able to handle the distance and the jealousy.
Stories like that can be found everywhere. And they have their happy ending, and all. But to have that, they did have to go through a list of different problems. But they worked together to maintain the relationship, and it made their love stronger. It's important to be open to each other about the problems each of you is facing, how you are handling the distance, and to find a solution. Love is the strongest weapon. If used smartly, it can get the relationship very far.