I agree that it sounds a lot like depersonalization from your brief description, but I also wonder if it could be an extended or repeated emotional flashback. An emotional flashback, in my experience, doesn't have the auditory or visual or other sensory cues of a complete experience (e.g. classic war veteran flashback, hears car backfiring and leaps into a crouched position, clutching imaginary gun). An emotional flashback is like the "feeling" analog to this, in the sense that the body is not reacting to a conscious or complete or triggered memory, but to a memory that may be in the subconscious or unconscious. So you have the emotional feeling that something has happened, but because the memory is not accessible, the feelings do not feel connected to it, and like they don't belong to you. And the emotional flashback to a past trauma can be dissociation or depersonalization itself, as those are often responses immediately after trauma, typically creative and excellent coping strategies.

I find what you're describing pretty distressing, no matter what it is, and it has sometimes helped for me to dig a little deeper into the thing, to see what it is trying to tell me. Could be your brain's way of trying to resolve this for you.