Last month, a female colleague yelled at me for using the F-word. In the middle of the office in front of everyone. It was ironic because she uses it ALL THE TIME. Also, this was the second instance of her disrespectfully yelling at me in front of other people (first instance was about me hanging my jacket too close to hers, she went ballistic asking me to remove it asap).

FYI - I never said "Fuck You" or anything directed at her personally. I was talking about how actual business performance is way off from the planned targets, and said something like HWhat the fuck are they even doing"

After this incident, I cut all unnecessary communication, and I avoided speaking to her at all, unless required for work. She didn't like that either, so 2 weeks after the incident, she reported me to HR for making her feel uncomfortable. Then HR (another lady) reprimanded me for using such language in office and making female colleagues feel uncomfortable. She never bothered to ask me for my side of the story. And she wants me to apologize to her.

Its been a week since the HR talk. I haven't apologized yet. What should I do? Should I be worried? I used to think she's a friend, then she suddenly pulls this off.