Maybe I didn't read this clearly enough, but it seems as though you "broke up" with Kris because she didn't always invite you/find ways to include you whenever she did things with mutual friends. Is that the case? It seems as though you were hurt not only that you weren't invited to the wedding, but that Kris either didn't tell you that you weren't invited or didn't pressure the bride to include you?
If I am reading that correctly, I think that you put way to much pressure on Kris. I am very good friends with a woman I work with, and, through her, have become very friendly with some other women. But she is better friends with them, and, while I admit that I sometimes feel a twinge of jealousy when she does stuff with them without me, I don't always have to be included to validate our friendship. Just like I don't always include her. We don't owe each other explanations; we're not married, we're friends. Honestly, if she started wondering and asking why she wasn't invited to every event that involved mutual friends, I would find her "clingy and desperate" to use your words.
While I do believe that you can cultivate friendships, deep, meaningful, lasting friendships are both organic and wax and wane. If you head out into the world looking for a "best friend" you are going to put too much pressure on the relationship and it is going to collapse. Instead, try to make lots of friends. Yes, it is more time consuming to meet lots of people and spread yourself over all of them, but then you have lots of people to do GNO's with, talk about families, etc. Who knows? Maybe some of them will become BFFs, and maybe not. But I think that confidence in your ability to make and keep friendships would do both you and your friendships a world of good.
Good luck.