Hello Vicki,
If you look at all the circumstances like...first the injury...excess amount of blood...knowing you are far from home...paramedics now involved and a hospital visit. This is an event that could certainly cause those few nasty chemical releases that tend to get us feeling out of whack and could easily slip one over the edge to some level of panic mode.
Everyone reacts different to blood. Many could possibly pass out just from the sight of it...I'm only guessing that you can handle the sight of something like that but given the rest of what's going on with being at a store and all the rest of it...it's compounding everything and certainly could have caused you to feel faint and a bit panicked.
Do your best to not dwell on all that was not so good about what happened but focus on the positive things like....you felt faint, but you didn't pass out...you had a bit of an emergency and you got help and got through it....this was kind of a major event considering all the factors...sounds to me like giving your history of anxiety and panic that even though you had a bad experience..for the most part you came through it like a champ!
Now you have something positive to draw on if something like this ever happens again, you survived it once and can certainly survive it again...It may have felt awful, but I say good job Vicki, you made it through it..let the bad memories of it fade and take away the fact that you are ok now...and I dare to say maybe even just a little stronger now. Take care and best wishes....Wingman