Chopin, I think your response to Anne was great. I was worried about how you'd take what she said, but I can tell you're trying here. I agree with her reading of your original post, and I too am concerned about your avoiding the shame of returning to a relation where you might have messed up in some way. And I think your T has the right idea about manipulative behavior.
I'm going to answer your questions by lumping the first and third together, then going to the second.
The words "selfish" and "offended" aren't really the right words to me, but there are some times where on the surface your behavior might be "selfish", and I wanted to use a time I was not so much offended but caught off-guard by something you posted as an example.
I don't remember exactly what it was about, but you were concerned by the unusual way in which your boss had requested a task from you -- or perhaps did not request a task, I don't remember -- anyway it was some kind of instruction that came from him while he was away. He was traveling to go to a family member's funeral. You kind of freaked out by some implications of what he said, which was unusual, and were reading into what he said and you were contemplating calling him for some reassurance about it.
Now, part of the reason my initial reaction was WHOA was that at that time, I was in the midst of a year in which I would go to four funerals and/or memorial services. One was an old but very very dear relative, the other three were taken before their time. I cannot adequately describe the grief present in the room where the body/ashes of someone who has died young lie (one was 12 years old). Three of them were family members, and of course, there is the accompanying horror of family politics and power plays that enter the mix at such a terrible time. So I could very much relate to your boss, the stress he must have been under. And when I thought about one of my coworkers calling me with a question about whether I was upset with them while I was away during those periods of grieving, I felt a lot of shock and... not anger, but frustration.
It's easy to think, "How selfish!" But from what I know about you, and certain things I can really relate to that you've talked about here, like having an emotionally distant mom, I also felt very strongly empathetic. From my perspective, what appeared to be happening was that you are so acutely aware of slight behavioral changes (probably an emotional survival mechanism from childhood), that the subtlest ones can send you into a tailspin and it feels unbearable not to know if those changes are because of you. Those unbearable feelings take over, and whatever is going on with the other person goes out the window, in a way. In one way you're very aware of the other person, in that you are perceptive of the details of their behavior and have a good memory for things they have revealed about themselves in the past. But in another, you aren't, because you can sort of let the part of you that is convinced that something has to do with you take over and build up steam. By the time a confrontation happens, you have this whole thing that's gone on in your head and it doesn't really give the other person a chance to actually be present as him/herself.
Now I don't claim to be totally accurate there, I am just telling you what I think, and being honest with you.
As for whether your posts have changed, no, I don't think so, I mean they are different but we all change over time. The one thing I might say is that this fear seems to occur more and more with people here at PC, rather than being more restricted to people IRL. For instance, your talking about feeling like a "pariah" on the couch. That's not how I feel about you at all, and in fact it's a little upsetting to see you declare that, because then what can I do? It seems to not matter how I really feel.
And I don't think it has to be all-or-nothing with how you deal with PC. Perhaps restricting it carefully... choose two or three days a week to come here, and DON'T come in between, not even as a lurker. And don't respond out of anger, just leave that thread/PM/whatever, and see if you're still angry by your next "PC day". Even if you are, you're probably going to be able to be more reasonable than you would be in the moment. Just a thought.
This is an intense place and I hope you find a way to relate that works well for YOU

.