I can strongly empathise OP.
Weak, unhappy, self-loathing people often overwhelm and oppress more than directly aggressive ones? Because you feel guilty for their unhappiness and "responsible".
My own parents were of that nature: really never turned into adults and didn't know the meaning of boundaries or of acting in a responsible way
(they'd vacillate between self-pity -asking their children for emotional reassurance and discussing "adult" matters with them and aggressive).
Basic things like getting up on time, giving their children clean smelling clothes, were beyond them.
It was awful: they expected their children to be the strong ones and they both depended on them socially (we were all academic high-achievers who played sports so they'd be obsessed with living socially "through" us) and were controlling and needy.
I agree with what you say on being "people-pleasing" as well: they were so desperate to be liked and so socially inept themselves they'd literally let family "friends" make unpleasant comments about their children and make us "make up" with the children who had bullied us so they would look good in front of the parents. I am disgusted at their weakness and will always be.
As I've got older, I think it's been helpful to gravitate to people who act as mentors rather than expecting to be "the strong one" all the time. Being kind to myself, and realizing I can be loved just for "being" not for "doing".
I went NC many years ago and I think that having those years of peace really saved me emotionally!