Hi rox, welcome to PC!!!
Is it possible that you're basing your self worth on being in a relationship at all??
Perhaps you could think about what a relationship gives you that stops you from feeling/being so self destructive?? What sort of gap it fills for you?? And from there you might be able to find different ways to get that for yourself without the "need" for a guy.
I think some of it might depend on what you mean by self destructive as well though. Kind of like.........is it destructive in the sense of behaving "recklessly" in drawing people to you, getting their attention so as you can feel less "alone"/noticed or maybe destructive in the sense that you're feeling depressed, you just don't care about yourself or what happens to you or maybe destructive in that you feel you deserve "punishment"/what you do to yourself..............???
But you are worth more/your wellbeing is worth more than any guy/than any relationship you know??!!
So just a few thoughts for now, if you want to tell us a bit more..............
You've certainly found a great site to come to for understanding and support..........so please don't hesitate to talk some more when you're ready.
And again..........welcome!!!

Alison