I think you should really try.
When I was 18 I went to a lot of trance parties, I was 1,94 tall (like now) and I looked a bit younger than 18, but I never had any problem / any ID-checking or something.
I've never seen an event in which they were strict on age. I think you can order your ticket for the next trance event right now, don't be afraid I'm sure it will work .
Furthermore, you don't take a big risk coz you're from the Netherlands ; in the worth case (ID-checking and they don't want to let you enter) you can just go home it's not like you come from China to Trance Energy and they don't want to let you enter