hey discovering, and

it does sound like your experience has been quite exhausting for you as well as taxing for your son; good for you for putting him first. i think you will find many members here can relate to your story. you are in good company. also, counseling for you and your son will be invaluable.
"I don't know when or how BPD developed or if it was just always there and not active until stresses brought it out?"
for all that our stories have in common, every person with BPD is different, as is every relationship. others who have been in lengthy relationships like yours describe things as "normal" for years. you ask a good question. it is generally believed that the origins of BPD can be traced to the ages of two or three. there are genetic factors from birth that may make a person more susceptible of course. if you are asking if BPD suddenly developed during your marriage, that is unlikely. BPD is a personality disorder, meaning traits are ingrained in her personality, which formed some time ago. of course this is all on a spectrum. traits may differ, not be present until they are, lessen or increase over time, etc. i encourage you to keep reading, there is plenty to be learned here.
in the meantime, we also have a legal board here:
https://bpdfamily.com/message_board/index.php?board=10.0as well as a coparenting board here:
https://bpdfamily.com/message_board/index.php?board=9.0you may find both useful. each board has all kinds of lessons and resources. the lessons on this board (leaving) are found within the links directly to the right.
welcome again, and please keep posting, discovery
