Unfortunately what's happened here is that your brain has learned something that puts you into "protect mode" given the right circumstances; the SNS fires up and basically puts the body into fight or flight mode but without conscious awareness of what's happening - which is where the anxiety part happens. You start feeling various physical issues (SNS is triggering those) because there's a disconnect between what your rational mind knows vs what the amygdala thinks it knows, hence seemingly uncontrollable fear, panic, and dread looming over you. It's a completely fucked situation but there's only one way to handle it and that's through extinguishing the fear by confronting it. If you try to run away from this anxiety or otherwise do whatever it takes to make it go away (rather than "sit in it") it will just further reinforce to the brain that it's something to fear. The end-goal here is to retrain the mind to stop freaking out over things that aren't rationally worth freaking out about. Like a person with a huge fear of dogs spending more and more time around dogs; eventually the immersion pays off and they no longer irrationally fear dogs. I highly recommend you avoid medication of any sort, it's moving the opposite direction from where you want to be, and they're mostly all benzo's which means there's an underlying physical and mental addiction component present at some point; not to mention they're really just masking the issue.
By and large you have to do what most people typically recommend: When the anxiety shows up and starts all the body/physical crap (which sucks), you need to exercise controlled breathing to help nudge the SNS/brain back into a calm state. It also helps to be 100% consciously aware of what's going on and know that it's anxiety and nothing else (because trust me, everything will be trying to trick you into thinking it's something more serious than it actually is). You also need to look deep down into where you think the anxiety might be originating from (age? existential crisis? future? it's clearly some kind of fear) and try and figure out what the connection is that triggers this. PTSD sufferers are basically dealing with the same thing.
Oh, and I recommend chamomile when you start feeling the edge. It's a very simple but usually effective non-medication based avenue to just chill you out a bit.
What's your caffeine habit like? This can be a very under-looked avenue but it's not rare whatsoever for people who've been regular coffee drinkers to just have something snap at some point where caffeine itself makes everything worse. If you drink coffee, start thinking about decaf or half-decaf.