Regarding close friendships, how do you react / respond to change?

I have a few friends I’ve known for 10+ years, and a few close friends I’ve known for less. I tend to have strong bonds with my closest friends, and sometimes I do not react/respond well to significant changes with frequency or quality of contact. With other friends, if I don’t hear from them for weeks or months, it’s no big deal me.

When there are changes in your closest friendships, how do you react / respond? How do you care for yourself when the changes feel difficult or uncomfortable?