I didn't identify until more recently either and I'm 48 years old. I believe we become fed up with toxic relating and having to defend our position all the time and things just crash.
While I do believe it's okay to set boundaries, I find myself having to justify them over and over. Whether it's being interrogated by complete strangers who find out that I'm not close to my family of origin, or saying "No," to something, or not wanting be the one doing all the legwork in a friendship because the various other persons "can't."
Hang in there. So glad you found this place.