I'm so sorry you are going through this. It's a terrible thing but you are not alone. In Holland you have access to free legal advice via the Juridisch Loket. They are also the place you register for legal aid. You can find out more about that here:
amsterdam-mamas.nl/articles/legal-aid-netherlands
If you decide to divorce then you can find more on the process here:
amsterdam-mamas.nl/articles/how-file-divorce-netherlands-part-1
amsterdam-mamas.nl/articles/how-file-divorce-netherlands-part-2
There are also custody issues you need to be aware of if you want to leave the country with your child:
amsterdam-mamas.nl/articles/moving-children-after-divorce
At some point you will need a lawyer, here is a list for you to start with:
amsterdam-mamas.nl/articles/mamas-recommend-family-lawyers
You don't need to press charges to have the incident recorded with the police. The record is very important as it will be called upon in any divorce and/or custody issues in the future. It seems that your husband is already denying what happened so the formal record becomes even more important.
Along with your huisarts (gp) you may also want to talk to your local GGD office as they will also be able to provide support.
The Blijfgroep and AriseNL are organisations specialising in domestic violence support.
I know that this must feel like the worst time to be making decisions and you probably want it all to go away while you process what happened. Unfortunately, the restraining order is only 10 days and that is the amount of time you have to get advice and make decisions to protect yourself and your child.
For moral support, there is the Amsterdam Mamas community on Facebook. You can reach their admin team at [email protected] if you need to make a post but want to remain anonymous.
What I can tell you, to answer your last question is that absolutely none of what has happened is down to you. None of it. Zero. You did not force him, drive him, incite him or goad him into attacking you. Nothing you said or did made him do it and you must not for a second assume any accountability for his actions. When he chose the action, he chose the consequences. He always had a choice. Whether consciously or not he chose to hit you. That is unacceptable behaviour and the most compassionate thing you can do for him right now is to hold him to the consequences of his behaviour. Your first priority is to protect yourself so that you can provide the best possible environment for your child.
If you feel that a therapist/counsellor would be helpful, check with The Amsterdam Mamas Community team for recommendations in your area or contact AccessNL who have a counsellor on call.
Whatever happens I wish you luck.