Yes, in my childhood and teenage years - though, uncaught.
Was this violent criminality (robbery, assault/battery, threatening, rape, murder, etc), or theft/drug use?
All my friends deserted me.
They deserted you because you told them to seek therapy (per your other answer)? Why would this have caused them to desert you?
I apologize in emails (for example) but don't really mean it - it's all a façade.
Have you ever felt remorse for any of the things you've done to cause harm to others?
No, but I do think that if I'd act out I'd be put in prison and so I push feelings/impulses away and self harm due to this.
So it sounds like you have a good understanding of the consequences of your behavior, and are able to modulate your actions as a result of this. That's a good indicator that you have solid impulse control, which is another diagnostic criteria for ASPD - a lack of impulse control, reckless disregard for the safety of yourself and others, etc. Can you hold a job? What's your highest level of education? How long have you been able to keep steady employment? (1yr, 2yrs, etc).
Another diagnostic factor is personal responsibility - someone with ASPD lacks responsibility and prefers not to undertake tasks that involve effort - such as employment. Much of the time, people with ASPD have a poor occupational history and tend to job-hop after 1 or 2 years, or to find work where they don't need to expend a lot of energy. Another way that is manifested is something known as a "parasitic lifestyle" which is to find someone else (your parents, a spouse, etc) to live with (kind of like mooching/freeloading off of them - hence the name) so that you don't have to worry about employment at all.
None of this is intended to be judgmental for the record. I thought I had ASPD for a long time, because I met a good portion of this criteria and still do. Mine ended up being schizoid personality disorder, but a side effect of that is I am extremely familiar with ASPD and its causes and differential diagnoses. One of the differential diagnoses for ASPD is actually PTSD, especially in men. Given that you're on a PTSD forum, it's worth pointing out.
But this is basically what I'm talking about when I say that your therapist is spouting bullshit. You don't "become antisocial" after having a strong feeling. That has nothing to do with ASPD at all. If you have ASPD, strong stressors will probably result in an exacerbation of your symptoms. But you don't "become" anti-social. You already would be anti-social. ASPD is all about your behaviors, and what you're doing. And, while a psychopath would undoubtedly be diagnosed with ASPD if it were relevant, most people with ASPD are not psychopaths. They are two separate things.
Do you frequently disregard the rules of society, the law, and other people? Are you frequently getting into fights, getting in trouble, losing friends, etc? Are you able to hold a job, live independently, etc? Those are the things you should be looking at if you're genuinely considering ASPD. It might be that you do have it, but I wouldn't listen to anyone who claims you'll "become anti-social" due to having strong emotions. That is not how it works. In fact, if you do have ASPD, strong emotions are probably not going to be a huge factor for you - most (but not all) people with ASPD lack strong emotionality.
To answer the question in your OP, though - yes, I've encountered a lot of people with ASPD. I thought I was one of those people for many years, so I sought out those who were similar to me. While I don't have ASPD, I have a lot in common with those who do. Namely, the lack of emotions, the lack of remorse, the laziness, the anhedonia/alexithymia, irresponsibility and impulsiveness. SZPD/ADHD will cause that, too! So there's lots of other factors that could be at play.
Don't listen to a clinician who isn't very careful about their diagnostic process and who throws out these terms in a manner that is frankly nonsensical.