@WeyAyeMan
You are shattered because a belief you held has been shown to be unfounded.
Victims of DV believe deep down that they are in control of the situation, that they can influence the behaviour of the criminal.
What you are afraid of is the loss of control over the situation now that he has been arrested. This is all entirely normal and to be expected. Such is the nature of fear and how we deal with it.
The secret is out. The future of the relationship is in the hands of police, social services, and a judge.
Please be aware of this as the next few days proceed, and please try your hardest not to minimise what he did to you when you go to court.
You need immediate help from the police to get a non-molestation order, and an occupation order stating who can be in your home (not him, obv).
You need to call Women's Aid 0808 2000 247 for advice and support.
Stay here on MN and you will get online support.

So sorry your dream has been dashed - you need to grieve this.
Take comfort in the fact that you can get through this and be a great mum to your little ones, free from the energy sapping presence of this man, the stress, the emotional and psychological upheaval, and the sight of someone committing criminal acts in their own home.