it is a frequently occurring emotional response
Idk if I even have adhd, but i feel like i have experiences that sound a lot like your description, but which feel like they vary a lot in frequency. Like last year there were a couple months when it felt almost constant, happening at least a couple times a week, but that feels very much like the exception and outside of that it's quite occasional, with a month or longer passing between occurences, so idk if maybe it's something else or just completely normal but yeah
Can't say I'm especially knowledgeable on anxiety disorders or PTSD but it does feel unlikely. Anxiety isn't really something I think I feel a whole lot of, with it being infrequent and generally low-intensity when I do experience it. Also it feels noticeably different to what I was thinking about here, which I guess feels more rawly emotional.