I'm desperate

I have 2 boys 1 who is almost 3 years old a 3 months old baby and I suffered from ppd and im getting help but when I suffering I hit my toddler maybe once and pushed him etc, and now he is very aggressive and im sure it's because of how I was, he hates me now. what can I do to make him forgive me and forget when I did to him? will he remember forever? I need help