Hey, thanks everyone, for continued concern and support.
I am still very sore on my left side from the incident, so I guess you are all right, something did indeed happen. I just don't know what. Maybe some bruised ribs and some spasms or something. The pain was really intense. My BP had dropped by the time I got to the ER, so I think it was just very high initially because I was agitated and scared about my heart.
I will not tell my therapist about this incident because I would feel too embarrassed. Plus, we have such important work to do in therapy right now, and I only get 1 hour a week with him, and I can't devote my time to stuff like this (in therapy I need to accomplish certain things in a timely way in order to sync up with the legal timetable--pressure!). Partly because I won't be bringing this up in therapy is why I asked all of your help in sorting this out! And I have gotten some great insights here and support. Thank you!