I don't know if there is a dedicated forum like this one. But I've been in some groups in other social media that are pretty much what you are describing and I dipped cos I don't think it is comparable to this. As in they are irredeemable. I'd stay away from those, not worth it.
There is a lot of romantization and hello kitty razors and teenage girls with terrible mental health just dragging eachother down with competition even
I don't know what exactly you mean with pro-choice regarding self harm. Here there are resoureces if you want to heal the wounds and make sure you do it right. The general consensus whenever I've seen it mentioned in other sh communities is do it if you must, if you do it take propper care of it and try other ways to cope first as it is Not healthy in the long run. It's short term relief of tension, if you find no other way then do it, I do it, but that's not bullshit that's just how it is. It's not good.
I think this is the consensus of this site too, there are plenty of threads on it you can vent whenever you want about it if it helps. But keep in mind that tho sh and suicide share a same space they are not comparable. hugs