Currently trying to work this one out myself dippy.
I think it's a bit more difficult if, like me, your parents didn't view you as loveable and worthwhile just for being you, like you weren't worth the bother of being held in mind.
But it's not impossible and in my case is still a work in progress (at 53).
But firstly it was about taking responsibility for my decisions, good and not so good. Not seeing those who'd let me down as wholly bad and me a victim, nor me as wholly good either. I'm capable of both good and bad behaviour but I strive to do the best I can always. That makes me feel good about myself. the better I feel about what I do, the more secure I feel about my relationship with me, and I look after myself more.
I've grown up a lot in the last couple of years as a newly single woman. I've done things alone that I'd never have done without a lot of control support from my then DH (got a much better job, sold a house, bought a house, booked a holiday abroad ON MY OWN, kicked a loser out of my life, turned down dates with yet more losers???..).
My relationship with responsibility still need work. I've always been attuned to people who need rescuing in some way and if I don't I feel guilt for not responding. But, like I said, it's a work in progress and a shit load of excellent therapy has helped enormously. Nowadays rather than beating myself up for whatever reason I hear my therapists voice reminding me that the person everyone else sees as the strong and capable woman really is that woman on the inside too. She helped me to nurture the 'young Wisey' that didn't get that when she needed it.
So that's where I'm at OP. I hope it makes sense to you, and I hope you don't give up trying to form that very important bond with you.