> if he has an anxiety problem, he would straightly start by talking about it
In my experience, with an OCD component with general anxiety, it can twist your thoughts so much that it's difficult to unpick what the root problem is, other than a general and overwhelming feeling of "Something's wrong". I've often likened it to having two threads running - one is your normal, rational thoughts, and the other is irrational/incoherent, anxiety fueled nonsense, which often overrides the first - but it took me months (if not more) to be able to articulate it in those terms and keep some semblance of a rational thought process rather than just going into a blind panic for no reason.
When it was first happening, it definitely felt like something of a physical origin, as I could feel my heart rate going up and up, my mouth going dry, and breathing wasn't easy (and you think the panic is _due_ to those symptoms). However, as I was getting very similar symptoms from trying to ignore certain recurring thoughts (just coupled with an overwhelming compulsion to do certain things in response), it pointed me at an anxiety-based cause pretty quickly. Without that side of it, I'd not sure when I'd've come to that conclusion.
I'm now more or less at the point where it's 'just' my OCD obsessions that set me off, which are at least foreseeable and thus somewhat more manageable, but I'll still occasionally have periods where all I feel is "something _very_ bad's about to happen"/"something's wrong"/"I need to be anywhere but here" for no apparent reason. The analogy in other post about hearing the boss music is apt - that's exactly how they feel. Thankfully they're not full-blown panic attacks (no shortness of breath or chest pain), but heart rate jumps ~40BPM, not having a wall behind me _really_ freaks me out, and I can't concentrate on anything else or really talk to anyone. They're short-lived (30 seconds-10 minutes), but it's a really sudden onset (it hits me like a wall) and I feel jumpy for the rest of the day.
Slowing my breathing helps - deliberately breathing in for 5s, then out for 5s, and trying to focus on that seems to shorten the duration, and in the situations where I can tell one is coming (OCD triggered - I usually feel increasingly tense rather than it being so sudden), it can sometimes prevent them. Drinking water also helps for those - my mouth going dry is one of the first physical things I notice, and that just increases the anxiety. Keeping my mouth wet for that period helps stop that feedback loop.