I'd say what you're doing is self-harming. Maybe not to the degree your friend is. But self-harm is self-harm. I also find the idea of using a razor or knife to cut myself difficult. However I'm a long-time hair puller. I've also pierced my skin with needles, I've ingested mildly toxic substances, & I've beat my head against walls to the extent that, over time, I developed Meniere's Disease (a condition of the inner ear) & tinnitus. Despite all of this, I don't typically think of myself as having been a self-harmer. (I'm not doing any of this anymore.) But when I actually think about it... I clearly have been.