I actually feel bad as I write this because it sounds as I give advice to you and it really should be the other way around, both agewise and plain wise. I sure would be a thousand times worse if I were in your place and following your calling, of giving some truth to the heterodox. Which is why I very rarely post there (or anywhere for that matter!).
Basically, anger, frustration and desperation are all feelings 100% caused by the Enemy. I think he is mad at you and the timing seems interesting, right after it seemed you, with the grace of God, had produced some fruit, with some very encouraging visits here from the outside and a particular one. And that seems to now go the other way again, perhaps because of what was going on in GH. How subtle and utterly hateful the Enemy is!
As for the people who give the step to the enemy to work his cruelty on you, I always found this incident from the life of elder Porphyrios very helpful:
A man was telling him how some people caused him so much bitterness, anger and frustration as they were doing him great injustices. The elder asked him:
"Imagine you walked on the road and suddenly saw your brother in front of you get attacked by malicious thieves. They would hit him and stab him until he was left bleeding on the sidewalk unconscious. What would you do? What would you do?"
The man answered that of course he would run to him and offer him help.
The elder replied, "would you hate him? Be angry at him? Kick him?"
"Of course not!", replied the man, not understanding how the elder could think this about him.
"This is exactly what happens to those people who cause you the anger. They are being attacked by the demons and it is a worse attack! We should love them more for it and pray for them"
I don't have any practical advice save the standard Orthodox Way remedies: Go to your SF, tell him exactly what happened and what your thoughts and feelings were when you posted whatever and follow his advice.
But I know that both the elders Porphyrios and Paisios often did not talk to certain visitors (and they were most of the time Orthodox visitors!) Perhaps, the decisions you made when you were calm, to put certain posters on ignore or refrain from posting in threads they participate is a very good idea. But the spiritual father knows best obviously!
Please forgive me if anything here is off-base or sounds judgemental. I honestly 100% am amazed that you kept your calm at certaint threads and posters. I absolutely wouldn't be able to do that. Careful with the slaps though

I think those tactics are strictly reserved for the spiritual heights of few and at situations graver than a thread on the internet
Again forgive me...