The key for me was self-acceptance.
I didn't really believe that no one else would accept me if I wasn't perfect (though I had been conditioned to believe that to be the case); in reality, I would not accept MYSELF if I was anything less than perfect.
It came back to the core work with my therapist. Forgiving myself for not being "enough" to make my mother happy/stop drinking. Actively stopping my own negative self-talk. Spending time only with people who reflected the best in me. Learning to take care of myself.
I was able to do these things without the outside pressure of a relationship, and I thank myself everyday for giving myself that gift (which did not feel like a gift at the time so much as a "sentence"). I was able to build a relationship with myself that was the foundation for all other relationships.
But the first step was acknowledging that the only person who actually expected me to be "perfect"...was me.