How do you develop or improve such core characteristics at 36yrs old?
It's never too late to grow up or grow into the person you want to be - once you decide you need to. That presupposes some self-awareness (that is non-existant apparently, in your parents). It is possible - not saying fast or easy all the time - but it is possible to grow into new attachment styles, basic identity characteristics, etc. It is possible (and likely) that you have heretofore unrecognized strengths that will help you along the way. They're unrecognized by yourself, simply because of the propaganda campaign waged by your parents who berate and criticize you for "being bad", "sick", unworthy... etc hogwash... all because you're NOT like them or the way they want you to be.
From where I sit, you're a bit ahead of the curve - an "early bloomer" - if you're starting this work at 36. What most of here are doing is exactly what you're beginning - figuring out what it is we need, figuring out how that's acquired, and in view of our relationships here - giving each other the things that "good enough parents" provide to help their children develop and grow into balanced, well-rounded people. Along the way, we talk about all kinds of things! Big life questions; theology; raising our own kids; and even some of the trivial mundane things, too. It's AMAZING the kinds of things that we discover our parents "should have" taught us.... but didn't. That in itself, is enough material for a book. Most of us, came up with strategies for coping with those deficits - or else got very, very, very lucky. Sometimes, it helps a lot just to stop and count those blessings.
You're going to be OK, SF. Collectively, there is enough experience among the currently active folks here that one or more of us, will absolutely "get" any dilemmas or questions or situations that come up; and we'll connect person to person. Many of us have been through the same thing. It can be pretty discouraging and disorienting sometimes, when you start this process. But PLEASE let us know when you're feeling that way, and one of us will drop in and offer comfort and support. It takes time to process this kind of thing all the way through - and to understand. So, first rule of healing is:
please take very good, gentle, kind care of yourself and your loved ones. This is very important.
Rule #2 is: give yourself some slack!! You are learning something new and are expected to make mistakes along the way - that's OK because you're learning. So, don't beat yourself up because you're not in 5 seconds or after reading a book or two, a black-belt master of life, OK, hon?