Borderline personality disorder and breaking up

Please help me. I have borderline personality disorder and can cope normally when I have a partner. I have not been single for the last 11 years ( Im 33). Not a day, even I have had three different partners during that period. Everytime I have felt that my relationsip was ending I had made sure I'd had an other partner to live with. Actually I have never lived alone.
My current relationship is coming to end and I have no 'safe'-nest to go to. I am living 1000miles away from my family and friends. I have no friends here at all. Only my cat, which I'd lose too.
Everytime my boyfriend tries softly to break up with me I loose it. I cut myself and have severe panic attacts. I am ever so affraid I will end up my life when having those terrifying 1-2 hour attacts. I have previously tried kill myself. But when I am calm I would never hurt myself. I really don't want to die if/when my relationship ends. How can I survive?