Apparently, you crossed the internet's line of decency. For that, you should be surprised, not apologetic (because I didn't know that was even possible!). I have seen some pretty nasty shi... eh stuff posted here before, but I couldn't watch more than 5 seconds of that video.
I think fair warning was posted, so even though it was going to get deleted, you did your due diligence. I think it's nice that you apologized for the people it really offended and made physically ill, but it was not posted with malice in mind, so everything should be copacetic with most people here.
I also agree that it takes a lot more than most people think to make a genuine public apology as you did. While I don't think it was necessary, it shows the type of person you are and I'm sure most people would rather have you on SM than not...