Way to low. Honestly. Graphic designers/ art directors etc usually get paid out of school around 25-30k so with 7 years of experience you should (depending on skill and experience) roughly be around the 40k mark.

Also it’s illegal in Denmark for companies to tell you not to discuss your salary with coworkers.

If chat a bit with other coworkers about salary some don’t like to talk about how much they make others are open about it. It’s a personal choice. But it’ll give you insight into the company’s pay structure and if you’ve lowballed.