Bad dream the night before running my marathon

[Oscen]

HI guys, I ran my first marathon about a week ago. Naturally, the night before I had some anxiety. I went and had dinner with a branch of my family I don't often see, who know my sister quite well. This is the sister who I suspect has BPD or NPD or at least fleas; so dominant was she when we were growing up that my IC speaks half in her voice, and half in M's.

Over dinner I felt anxious as I felt I had to give updates of all my immediate family, who I am trying to go NC with, but didn't feel I could explain that to the family I was having dinner with. In particular, I have a young niece (maybe a second cousin once removed? hazy on the connection there) who regularly texts my sister.
I felt completely on edge, worried about what that sister might have said about me to her. Probably egotistical of me... but my sister is very frank about her opinions of others. She used to offload loads of her thoughts of others onto me.

That night, I had a bad dream, which is rare for me. My upper chest was tightened and collapsed and my breath was shallow, and I drifted out of sleep into the half-awake, almost lucid dream-state where I sometimes have interactions with my shadow. I was looking at myself asleep in bed, with a big black shadow crouched on my chest. I remember thinking: "It's a leech". It was sucking the breath, life and energy out of me. I knew it was my sister, though it didn't resemble her. Dream logic!
I've heard people say that problems with the chest are fear, and problems in the gut are anxiety. I think I have a real fear of how I feel when I'm around my family.
I don't want to return to feeling helpless and worthless again, as I did when I was a child.

I don't know that this means that my sister is an emotional leech, per se, but it was a physical representation of how I felt towards her at that dinner.
A shadowy figure, feeding on me, draining me of life.