Questioning Reality: My Experience with Dissociation

A few months ago now, I was at a restaurant with a friend. It was a place I’d worked prior to where I work now, so I know most of the people I saw hosting and serving. We were sat at our table, and after a few minutes our server came out. I don’t know why.. but for some reason I just felt off. My friend was in the middle of talking, when suddenly, everything got blurry. Everything was dark and fuzzy and each word she said was echoed and muffled like it came from a room down a hall. With this sensation came this wave of fear, as for a good moment, I couldn’t for the life of me believe my friend was real. It was like I’d gone back inside of my own head, like I was inside my head watching everything on a screen. I was watching her mouth, trying to focus on the words she was saying, but I just couldn’t. It was like I was sure I was in a dream or a simulation. She just didn’t feel human. This is the first time I experienced something like this so strongly. I’ll often teeter on the edge of questioning if I’m real or if whatever around me is real, but it’s like I always knew better I guess. Yet in this situation, I really was doubting the validity of what I was seeing and experiencing. It only lasted like 5 minutes, but I had a couple particularly bad instances since then as well that were longer, but not quite as intense. Is this cause for concern?