You don't have your own back, OP, so it's too scary if the idea of them leaving isn't in your control. So you take charge of that idea, and shove them away anyway.
If you had your own back, you'd be able to handle the idea of being 'made single' better.
You've learned to dismiss your own feelings because of the way your parents were. You saying 'Love me, please, I need your love now' was always de-prioritised in favour of something else.
I suspect that the relationships you've had were with incompatible partners, but you have taken that to mean there's something wrong with you. There isn't. Accept what is really happening: each of them has either been someone you didn't really want, or someone who upset you. You've expressed these things sideways (ie via drama, rather than just saying it), resulting in them leaving you.
My counsellor said to me 'The only thing that's wrong with you is that you think there's something wrong with you.'
What if it was right to push your previous partners away? What if that, in fact, followed your true feelings, the ones you don't accept or express plainly? The ones you think are 'fucked up'?
What if the truth is that the right person for you will be defined by the fact that you don't push them away, so you don't feel faulty when you're with them?