jmif,
It's difficult to give you much of an answer with so many generalities, but I'll try.
What you seem to be describing sounds very much like a classic pain-body response from your SIL.
You write: "I do something (that seems insignificant to me) and she makes it out to be I purposely did this to hurt her, and there is an explosion, again."
"Pain bodies love intimate relationships and *families* because that is where they get most of their food. ***It is hard to resist another person's pain-body that is determined to draw you into a reaction.***" [http://P. 148|http://P. 148] (emphasis is mine)
My situation is not quite the same, but I can see some similarities between what you are facing and what I need to face differently.I have been spending this week delving into these ideas because I have a relationship where I need to learn how to deal with someone who is deeply unconscious and in the grip of her pain-body. Our dynamic of confrontation has been a cycle of blame and defensiveness for a number of years, and since I have always been relatively passive, she has been verbally and emotionally abusive and I have taken it because I am deeply connected to her child (who is very young). I'm not a complete doormat, but due to my upbringing, when the screaming begins, I freeze and have been unable to respond much beyond monosyllables.
We are each dealing with people who are unconscious. When they attack, it isn't THEM, it is the pain-body.
"It requires a high degree of Presence to avoid reacting when confronted by someone with such an active pain-body." [174}
To be honest, although I'm into chapter 6 now, I haven't gotten much further than that page, so there may still be further guidance, but I would like to share what I have come to at this point.
I love this person. When she is not in the claws of this horrible monster, she is one of the most wonderful people on this planet. When she is in this pain-body state, she is terrifying to me. And interestingly enough, just as I was beginning to feel like I had a clue about being Present, a situation has flared between us where it is highly likely that the next time we are in the same physical location, her pain-body is going to come after me, hard.
I have decided that, should this occur, I will do all that I can and use every trick that I know to remain embodied and Present with her. (I usually disassociate in conflict) Should things escalate to where she begins her screaming, I will tell her that I love her, that I wish to work through this problem, but that her screaming verbal abuse and unacceptable. I am leaving. And I will have to walk out and leave.
I'm trying to not go into the future, here, but the fact is that I need to have a game plan for this situation. My suspicion is that she'll follow me out, screaming, as she's done it to others. I choose to see HER - the true HER - with Compassion and I will NOT get into the blame, explain and defend game. Her pain-body will NOT want me to get away, because that is depriving it of the juice. We tend to use email a lot, so I will probably send a note explaining why I left and what my limits are for interacting with her.
Since I am the one who is awakening, it is my responsibility to set appropriate boundaries for how I am willing to be treated. Allowing this behavior to continue is poison to BOTH of us. I know that I can't change her or her behavior, but I can change how I am with her.
So I don't know if you see your SIL in my friend. I don't know if this is enough of an answer for me, let alone any kind of help for you! But if it helps.. or if it sparks any thougts and ideas in you, please share them. Thanks. T.