Professor got in my face and yelled at me

Long story:
I’m a lab assistant at my university and one day some of my coworkers who are underclassmen asked me about my experience with a professor I had taken a couple classes with. I told them that every class that professor teaches is hard and that one specific class, is a “flipped” course in which students have teach themselves the material and come to class ready to just answer questions and do classwork. I also mentioned that in that particular class the professor would get frustrated when students asked her questions during class time (so much so that she would yell at whoever asked her a question and in one instance became so frustrated that she stabbed the white board with her expo marker and could no longer write with the marker because the tip was completely sunken in). I also mentioned that this particular class put me under so much stress that it caused me to develop anxiety. Everything that I told my coworkers was my honest experience with said professor.

 It is not the first time I've told others at work about my experience while taking classes with this professor as well as with any of my other professors (in fact, on that same day I had talked about many of my previous professors and my time in their classrooms). Somehow one professor who manages some of the labs found out that I was talking about that particular professor (I'm not sure what exactly she heard or how much of what I said she heard) and decided to get right in my face and yell at me to stop talking about said professor because she didn't like what I said. After having yelled at me she just briskly walked away. When she confronted me, I was standing right next to my coworker and I noticed that even my coworker had to pull her head back because of how loud and close the professor got to me/us. My ears were also ringing for a few moments.

 I am not upset at the fact that whatever I said got out because I don't think I made any personal attacks, I simply talked about my experience in that particular professor's class. What upsets me is that the way the professor confronted me has really increased my stress levels and anxiety to the point that my blood pressure has risen. I am also experiencing dizzy spells, fatigue, and aches all over my body. I suspect that this is due to my anxiety. I have been stressing over this incident for the past couple of days and I'm not sure what to do.

 For now I've decided to go speak with a counselor to try and calm down and seek a different perspective on the situation. I'm also going to discuss the situation with one of my superiors at work and ask her for advice as well as get her perspective on the situation. I don't want to make any rash decisions or actions based on poor judgement and wild emotions. I am not comfortable enough to talk to the professor who confronted me (at least not 1-on-1). I'd like to try and get courageous enough to talk about this incident with my PI, but only if my co-worker (who is my witness) agrees to come along with me to support my case. I'm not sure if my PI can do much of anything or will do much of anything because they are very close to this professor who lashed out at me and this professor is also the head of one of the major departments on campus. Can anyone give me any suggestions on what I should do? Do I contact the Dean? (Is there even enough basis to do this?)

It appears that you need to seek counselling.

You had a bad experience with a wacko professor. You can talk to your PI about how upset you are, but you need to do something about your obsession with that moment. Imagine what other inappropriate behaviors that prof had done and assume you are not the first one to have that experience with her. Also, maybe tell these teacher stabbing the marker stories somewhere else. No need to involve Dean.