Hello lucidmoon: I see this is your first post here on PC. Welcome to Psych Central. The Anxiety, Panic & Phobias forum, here on PC, may also be one that will be of interest to you. Here's a link:

https://psychcentralforums.com/anxie...c-and-phobias/

I'm sorry but we here on PC cannot offer mental health diagnoses. Plus I'm not a mental health professional. So I can't suggest whether or not what you are experiencing might constitute PTSD. That is a determination that is going to have to be made by your psychiatrist & therapist.

What I can say is that as long as you persist in not talking about that event two and a half years ago (as well as what has gone on since) the longer you're likely to continue having problems with this. Take it from me. I have a very long history of keeping secrets. I'm an old person whose been doing it all his life. And I'll tell you it has taken its toll.

Perhaps, with the passage of enough time, what you are struggling with will all simply fade by itself into the background of your life. But clearly, so far at least, it is still causing you large amounts of anxiety along with (it sounds like) guilt & shame. Whatever it was you said on the internet that got all of this started, believe me, the odds are the mental health professionals in your life have heard much worse. The time has come to throw open the doors & windows, so to speak, & let the sunshine in. I hope you do.

Here are links to 3 articles, from Psych Central's archives, that (hopefully) may be of some help:

6 Ways to Open Up and Talk in Therapy

How to Deal with the Aftermath of Shame

Coping with Guilt | Psych Central

I hope you find PC to be of benefit.