Separation anxiety and trauma

Hello fellow IM's

My son and I had a fall a few weeks ago, which resulted in me breaking my arm and needing surgery. He saw me leave in an ambulance and separated for 3 days. He has just turned 2.
Since the accident he has learnt how to climb out of the cot and come in at all hours wanting me. If I'm not on view he constantly calls for me, and if he can't find me it ends in tears.
I know this is separation anxiety and trauma. But I don't know how to reassure him and make him feel safe again.
Please help.