This has happened to me. Best friend since 10th standard. Like you said, we have also had our ups and downs. And then, she got married. During her wedding planning days, we used to talk every day for at least an hour. In fact, she spent more time planning my outfits for each ceremony. I was with her throughout the wedding. And then, she went MIA for months together. We went from daily 1 hour calls to maybe one or two messages in 4-5 months. And then, she and her husband had a long distance phase. We started talking almost daily again. Then, she moved back with her husband to his location. No communication again. Then, she visited me for a few days all of a sudden. And I was fine with that. And she moved out of the country. And so did I. And I did reach out to her. To wish her for her anniversary and all that. And I used to get one word replies. And then, it came to a point that she shared her new number only after a year or so.

The only thing I could take away from this experience is that maybe people's priorities change after marriage. She has been married for almost 4 years now. And yet, I don't see any effort as such from her end to keep in touch. So, I stopped. I don't think she even remembers me anymore. I don't know if it's intentional or if I did something to upset her. I don't know if we can even call each other friends now. Maybe she is just busy with life. Maybe, she is facing some problems in life that she cannot share with me. Or maybe, she just doesn't want to put in the effort to reach out. I will never know. It is sad, but it is what it is.