To start, let go of self-blame and regret. These are natural feelings once you come to understand the true nature of a narcissit.
Chances are when you got involved with your partner you had no idea what you were getting into. Narcissists are skilled at drawing people in and hiding their true nature, for a while.
Sometimes just reading about narcissim can feel like a blanket of darkness has been lifted and you can start to see him for what he really is.
Before you can walk out the door you need to be sure you can safely remove yourself. Narcissists can become angry or impatient when things do not go their way.
Organisation such as women's aid are great and can offer emotional support and guidance (including financial but also speak to universal credit agencies) to prepare you.
(The below link has some email addresses if you feel more comfortable using those)
www.nhs.uk/live-well/healthy-body/getting-help-for-domestic-violence/
www.gov.uk/guidance/domestic-abuse-how-to-get-help?gclsrc=aw.ds&gclid=Cj0KCQjw8IaGBhCHARIsAGIRRYrQkz5TvCR6d6gCTE8lHmx1PYYRlqqPqyKWSBZ0MovX9JqoE9hVAZ4aAmqREALw_wcB
www.womensaid.org.uk/domestic-abuse-directory/
Do you have a support network around you that could help when you are ready to leave?
Familiarise your self with the tactics he will try to use to stop you from leaving. Be prepared for begging/ promises of change/ putting the blame on you for 'breaking up the family'. These tactics can confuse you, make you question your sense of reality, and damage your self-esteem.
link:Preparing to Leave A Narcissist
When you are in a relationship with a narcissist, they reel you in and hooked you. Each time you try to escape the hook; you will be ‘love bombed’ back into the abusive cycle.
Going no contact is the goal, but with your daughter I understand may not be possible.
Be prepared for him to use his own child as a weapon against you. He will try to influence, undermine and alienate her from you. "Don't listen to your mother she's a mad bitch" etc.
Emotional abuse leaves scars you don't see
It doesn't leave a visible bruise. There is no physical scar.
But the pain and long-term effects of emotional abuse on children are real and it is most felt as the child grows older and is at risk of repeating the same abuse that was learned (common in boys as they become men) or becoming a victim of further abuse (common in girls who become women).
Ripping yourself away from a relationship is incredibly brave. Don't be hard on yourself if it takes time. You are doing the best thing to protect your daughter.
(Sorry the wall of text and links, I just want to be sure to cover the right things)