I(18NB) have a coworker(F20-22ish) who was assigned as my "buddy" when I started a new job. We were polar opposites but got along pretty well as far as I can tell. Although we've never spent time together outside of work. I guess because she seemed genuine and sincere to me, I figured we were friends. But I guess I have attachment issues or something because tonight I saw her walking to dinner with another coworker(M18-19)ish, whom I also get along with pretty well, and I felt what I can only describe as jealousy. Like, suddenly I was incredibly pissed, I took an hour long walk in the freezing cold to try to calm down, only to glance in the window of the eatery and see them sitting together and that set me off again. There is no rational reason for me to be upset right? He's a super funny chill dude, and we joke around a lot. She is also very nice and supportive. I should not be upset that they're hanging out together without me. I'm also in a long term relationship, so there's no reason for me to be jealous of them having a relationship.

But I'm boiling inside. Any support or comments are welcome.