I’ve been acused of deliberately pushing people away. Is that a symptom of an attachment disorder?

It can be. People with attachment disorders often play ‘come here, go away’ without meaning to and often without even realizing they’re doing it. They often vascilate between the panic of being suffocated or engulfed by the other person and the panic of feeling abandoned by them. During periods of feeling engulfed, pushing the other person away is quite common.