It's quite hard reading these posts, this is a subject i've been trying to understand for such a long time. I've never self harmed, but my dp has. He started as a teenager. When we got together we were at university and it was obvious that he had scars. I knew he'd had depression, but self harm was something i felt i couldn't cope with and didn't want to think about. We got together, and i always said that i'd be there whatever, help and support him, but couldn't cope with that side of his depression.
A year ago, he had a sudden breakdown and self harmed for the first time in 12 years, but this time worse than ever, so badly that he collapsed, lost alot of blood and was taken to a psychiatric hospital where he spent several weeks. I found him, and i was with my babies. I was so so angry at first, i felt that it was the end of our relationship, that if this was the way he dealt with his depression instead of talking to me or getting help, that i couldn't be with him as i didn't want my children to see this and i didnt' want to have to explain this to them.
While he was in hospital though, i started reading about it, why people do it, and i began to understand his reasons and i realised that my ultimatum to him was the worst thing i could have done. We've talked about it alot since. I still feel upset by the scars and by the memory of finding him, but in a year alot has changed. I know it could happen again, and it does scare me, but i also understand it a bit more now. He had CAT therapy, and it was so good for him - at the moment he has other coping strategies that are working , and so he doesn't feel its somethign he needs. For him, the thing that changed was finding an alternative, and realising that he couldn't supress those feelings, he had to learn to live with them, which is what i'm trying to do too.
Getting help can be so hard, and it depends so much on who you see. I'd definitely recommend CAT (cognitive analytic therapy), and i wish i'd faced up to all this before dp became so ill, so i think that if you're worried that it will ever take over or get too much, its always worth speaking to someone before that point.