AIO for being upset that my coworkers were talking about me?

This isn’t as bad as the title seems but essentially last week I was annoyed by something at work. I didn’t yell, scream or anything.. just tossed my headphones aside and walked away.

I went downstairs for a bit and a coworker came and sat beside me with her computer right in front of me. Not that I was lurking but she sat immediately to my left.

On her screen was a few messages with secondary coworker, who is a very good friend of mine.

Essentially my friend said to the girl beside me “I don’t know why that was such a big deal”

In response my coworker said “I’m just going to be happy when I go downstairs”

These were sent moments after I left to go downstairs while annoyed with my computer.

This has sent me spiralling and I truly feel really hurt about it.

And to be clear the messages themselves aren’t bad at all - but I’m upset someone I consider a really good friend was even talking behind my back - even if it’s not inherently awful.

Am I over reacting?