you can manage your bpd and it will take time.
i had pretty bad tendencies and the best thing for me is avoiding substances, choosing good coping mechanisms like if you feel stressed and in a bad mood/fixating on something do something positive like take a bath or shower, do some cleaning, work out.
bpd is lonely, it's unforgiving. remember the only person who can be your one true best friend is yourself and maybe God if you're into that. seeking validation from others is never a satisfying route.