its painful and hard to achieve. i have a friend who attempted that way and was unsuccessful, she's doing much better now but it was not a good experience by any means. she was rushed to the hospital and had to get a shit ton of stitches and spent quite a while in a psych ward.
i know hospitalization is something most want to avoid but if you can access therapy/counseling/help of any kind please try. i don't want to sound preachy but this struck a chord with me as someone who had a close friend try to ctb this way <3