Blimey, you're 'brave'! I go to great lengths to cover up my arms, even wearing a long-sleeved top to the gym - which is not in the least bit comfortable. I also make sure I've ALWAYS got a cardigan on when at home. That would be my worst nightmare actually, people 'finding out'.
With regards to controlling how more and more people find out, this will sound stupid, but maybe just cover up?
As a side note, really think about what you're doing. Think about when you're older and have children, and have to explain to them why you have scars all over your arms.
That's the main thought that's stopping me from doing it at the moment, and also the realisation that it doesn't actually achieve ANYTHING!
You do sound like you want people to know. If that's the case, please go to your doctor, and they will refer you to someone who can help.
Best of luck :)