My son has nightmares after police raid - From Anon Mum

My partner was arrested in August and prior to his arrest our house was raided by the Police in the early hours. I was not aware that my partner was a wanted man although I knew he had been staying with friends for a few days because we hadn't been getting along. The raid was horrendous and I was petrified. The impact this has had on our young one has been awful. He has been wetting the bed, having nightmares and has become very withdrawn. He is petrified every time he sees a police officer and cowers when he sees a police van or car. I wanted my baby to grow up feeling confident that he could approach the police if any time in his life he ran in to danger. I know that they have to do their job but they literally turned my house upside down and my baby was screaming and wetting himself. 
My partner (now ex ) is now on remand in prison and the consequences of his actions has put our baby in to crisis. Before this he was a happy little one and was outgoing. I cannot forgive his dad for what he has put us through and there will be no prison visiting from me or his son for the foreseeable future. 
I keep googling to find others that have been in my situation and how they coped with the trauma. I am finding it incredibly hard to cope but my main worry is my son. I do not want him to grow up being scared of the police.