Being a person diagnosed with social phobia I thought that myself many years ago. All the SSRIs and SRNIs actually made whole thing worse.
Went through brain CT, EMG and some other tests and after some months psychiatrist gave me F40.2 (social phobia) stamp.
Went through various medications that made things much worse (yeah, all these medications actually tried to retain serotonin in the brain). Rivotril and other drugs that actually "disable" the brain work, but they aren't the solution. Being extremely tired also works, but it is not very practical.
It's rather debilitating illness and my life went to hell.
I'm not sure what caused that. I've actually acted as a project manager in my early twenties and everything was fine (I could handle meetings and all that idiocy just fine). Then it all went downhill and I can't tell if the onset of these symptoms was gradual (and I was just simply ignoring them) or if they appeared suddenly.
but again, i basically have no idea. however, i honestly whish you all the best.
I can see how you would jump to the assumption that there is something "wrong" in the person's life, as this is a universal reference point; Something bad happens in your life, and you feel bad about it.
But the fact is that most mental illnesses generally aren't a results of anything like what you've described.
There's no meaning behind them, and they're not rational - which is one of the reasons why they are described as illnesses.
This, in addition to severity, is some of the difference between an anxiety disorder and an anxious mood.
So the assumption made is basically dependent on your healthy perspective, and does not take into account the experience of people affected by mental illness.
If you really don't know much about mental illnesses (as you say in your post) I urge you to try to read up, as ignorance and stigma (which is to some extent a result of the former) are huge problems, even though mental illness is very common and affects around 20% of people, depending in the source (NIMH says 18.6 percent of all U.S. adults had a mental illness the previous year in 2012 [0]).
[0]: http://www.nimh.nih.gov/health/statistics/prevalence/any-men...
What's worse, this can lead to a whole range of phobias (I'm in the middle of this theater. What if I have an attack? Then you start having one. Now you're afraid of theaters and theater-like spaces).
It can take many, many years for people to learn how to "talk themselves down" out of this (or, more accurately, to endure the onset of one without letting it get full blown). It's not life threatening, but it's a very serious illness indeed.
And yeah, often you don't look at people, wear headphones or do other things like that. That's when you're doing "well" and not having panic attacks. When you've learned how to manage it.
In my case my attacks turned out to be related to a disorder of the autonomic nervous system, which (among lots of other things) results in my response system overreacting to stimuli. It took me a long time to get diagnosed and I've learned to cope by rationalizing my panicky feelings as nothing more than flawed biology. I know that there's nothing really wrong, and I can calm myself down, telling myself it's just my screwed up vagus nerve, before an attack becomes full-blown. Thanks to that I was eventually able to taper off taking Xanax regularly.
But while going through that process I had days where I couldn't even work, and even had a boss drive me to an urgent care place once in a full-blown attack. The work at the time was definitely stressful, but I think the panic attacks exacerbated the work more than the other way around.