((((((((((vetswife))))))))))))
I have no idea what was said, but I've done the same thing. Way back when, I didn't know what SI meant either - so you're not alone in that, ok?
I think your apology is more than accepted ... we all say things we regret. Go easy on yourself.
Self-injury is something that is hard to understand for a lot of people... even for people who are "under it's influence" (because it is an addictive behaviour).

If you have any questions about it at all, I can always help you out if you'd like.