That's a scary experience. I've never had to go to the ER from cutting (nor from anything else either) but I do know what it's like to cut too deep unexpectedly (though in my case I was drunk and didn't feel the pain)...

Sometimes it seems like SI is the *only* thing to do. You know about the coping mechanisms but you dont want to do them because it's the SI you want.I think at times like this the 'addictive' nature of SI comes into play because you feel you need to SI and nothing else will work... in my case I want the pain, I want to see the blood and the cuts. How could distractions such as having hot baths remove that? even if I work through it at one point, the urge builds up day after day until I even dream about it.

So you're not alone in giving into SI, remember it was just a slip-up and you did well getting through those two weeks without SI, and you can do it again. if you can , maybe consider limitingthe sharpness of the things you use so that the same amount of damage can't be done again. Or maybe you will modulate it next time anyway and not allow yourself to inflict bad wounds because of the fright you got this time. Please take care anyway, and look after your wounds.