Please don't try anymore, it just makes things worse very quickly. It might seem like SI is helping but it's just adding to your problems, not dealing with them. SI started the same way for me. My theory on why you and I couldn't "make it bleed" at first was hesitation. Some part of you doesn't want to do this. Think about it, think past the urge and try to figure out what this will really do for you. I know this probably isn't what you want to hear. SI feels like an answer or escape, you may not want to try anything else or ignore the urge. But please try, I know from experience it just makes things harder. It will consume your life. If you're not SI-ing, you're thinking about it. If for even a second you're not thinking about it directly, you're trying to hide the scars or worrying that someone will see them. That adds stress, which will fuel not only the urges but the things that led you to SI in the first place. It doesn't help in the long run.
Let me know how you're doing.