As this relates to international law - specifically, international custody law - it is admittedly out of my realm of expertise. That said, here is what I would attempt to do (although I have no knowledge as to whether the applicable law will allow it).

First, as to the child support claim, I don't think that filing and even be awarded something is really an issue. Your problem is being able to collect on the judgment. In other words, an English court my grant you child support, but there's no authority to enforce it. Thus, you'd have to try to get a Dutch court to enforce any judgment that you received. Hopefully there is some agreement or understanding in place whereby the courts of the two countries give any legal orders full faith and credit. This would mean that a Dutch court could enforce an English order for child support.

If you are awarded any type of child support, I would assume it can be made retroactive, but it will oprobably only go back to the point where you two split up (I'm assuming you lived together).

Your best bet is to talk to both a Dutch and an English lawyer to see which legal system offers the best chance for you to collect and go from there. Good luck!