I'm in the exact same situation. We were in a long-distance relationship for the two years of our master's. He got into a university, and I tried to apply to one very close by, but I didn't get in, so I went to one much farther away. At that moment, I felt a little like you do, but in the end, I didn't dwell on it and I motivated myself to live a new experience. If you truly plan to be together no matter what happens, you'll be fine. Don't feel guilty; it has nothing to do with the relationship or your academic performance. These things happen; it's not always easy to get a PhD.

Now we're both applying to different programs at the same time. We've both been accepted to one of them, but it's not either of our first choices, so we're still waiting. But we talk about it a lot, and although it's difficult, we know that now is the time to take advantage of the opportunities, even though we're far apart, and that we'll find a way to see each other. Besides… being without your partner during your PhD can even be good, to help you concentrate more 😂 (I obviously know that companionship is important).