Welcome to the community, Journey-Man. Thanks for sharing.

You're in good company, lots of us have experienced sibling on sibling abuse (I get irked when people believe that siblings are a built-in group of besties )
The thing that stuck out to me most about your post is how you, from a neuro-psychological (Is that even a word?) can "feel" what is happening to other people. I, too experience this and always wondered if I'm just a fine-tuned empath, overly-sensitive, or if it is just normal.
It's a blessing and a curse. Feeling others' pain (In addition to my own) is a burden, but it allows me to have a finesse with people that is pretty unique.