Sorry to hear about your the abrupt ending that is really terrible.

Maybe your therapist has a point. Would it help if you concluded that he’s moving away was an an underlying anxiety issue with himself? There’s nothing, no amount of love you could have gave to make him stay. Do some research into commitment phobia maybe you’ll get a better idea of the condition

As with all breakups distance yourself from him and cut contact,2 you have done nothing wrong yet he will have to carry around the guilt of his actions for the rest of his life. Hang in there, be kind to yourself and focus on your own wellbeing, sending you light and love