I agree people need to do things for themselves. This way of relating with oneself, however, this sounds like it could be related to dissociation and having splits/different parts that are in conflict with one another.

If thats the case, imo, the solution would be personality integration. With integration, a person has new capacities.

I dont think most therapies truly help with this sort of thing. If a therapist is too kind or giving and supportive, a person never has a chance to assimilate their aggression. With aggression capabilities comes agency. Without this capacity, some can only direct aggression in indirect ways, but usually at oneself, which manifests as self destructive behavior. Those inpulses are split off, were split off, long ago and sort of get encapsulated from other parts of self.

Language can offer clues as to what might be going on inside, I agree.