What you have to remember is that the court won't do anything for you or for your ex (even if it feels like it) but will only look at the interest of your dd. Their priority is to minimise change to their lives, which is why they most always favour the child staying in the country, because it means staying to what is familiar to them.
In your situation, whichever way the court was to rule, your daughter was going to experience change and loss. If she'd moved to the Netherlands with you, she would have experienced missing her dad as well as having to adjust to a new life. That's how the judge would have seen it.
Sadly, the more time passes, the more she settles in her new life, the harder it will be for you to evidence to a judge that another change would be better for her than her settled status, at home, in school, with extended family on her father's side, with her friends etc...
Unless you can evidence that your ex is abusive and therefore living with him is hurtful to her, you need to accept that you are going to struggle gaining custody, let alone being able to take her with you to the Netherlands.
You are better off putting your efforts in setting regular visits, coming to the UK eow, and making these long week-ends a top quality time together. Same with holidays. Hopefully you'll then be able to have her for a week on holiday in the UK and gradually might be able to agree with your ex or ask a judge for her to come to the Netherlands.
Who knows, when she is older, she might decide herself she would rather live with you, but as it is now, you deciding to move to the Netherlands assuming that you could take your dd has not gone in your favour and her father was probably able to show the court that you had been planning to do so.