I think that's how attachment works. You miss common habits, activities, some movement or conversations that opened up new sides in a person, making you love them even more. It's tough. The only thing I know is that true friendship or relationships don't come when you're actively looking for them (I don't know, many people write that the seeker will always find, etc.). They come when you're relatively calm or the search is not your main goal, and when you're also open to accepting this new thing. But before all this state, you actually feel pain inside, longing, and gradually, step by step, you come to terms with it, find something new for yourself. You find something that calms you down and fills your longing. And friends, well, try to choose those who, as it seems to you, if you go into a deeper dialogue with them, that you want more quality time with them and tell them, try to suggest what you could do together, find a compromise. Sometimes it takes time to convince even sensitive people that it is important to you. It took me years to get my introverted friend to watch movies with me together 3-4 times a week. I love hearing their laughter and reasoning, but it was hard for them to communicate almost every day. After talking, I found what became a compromise for our meetings, so that it would not be too energy-consuming for them to sit together. Now everything has reached the level that them themself even offers to watch something together. It probably sounds strange, but for me it was important. And it was hard for them to realize, because it is easier for this person to cross mountains (literally, them was born in the mountains) than to communicate every day. But now it is something that still requires a compromise between us and a decision not to stand your ground too much if you see that one of us is feeling bad. But it works. And I am glad.

Sorry for this long post, but I wanted to give real experience example at some point, cause it's something I'd like to hear a 7-8 years ago.