Hello Althuzia: Your post reminded me of a reply in a newspaper advice column I once read. A reader had written in saying that she was x number of years old. She wrote that she was thinking of going back to school. But she wondered if she'd be too old when she graduated. In her reply, the columnist wrote: so how old will you be in x number of years if you don't go to school?
Of course, there are always what-ifs. One never knows where a venture will lead when one is first starting out. And having had an unsuccessful experience previously does make the whole affair seem more risky. But at 25 you're still very young (take my word for it...) You're certainly not too old to be giving school another try, assuming that this is something you want to do.
Many years ago, when I was your age, I was in-&-out of college like a shuttlecock. I had very undistinguished academic career to say the least! The difference, I suppose, was that I was paying for it myself. So, if I wasted a bunch of money in the process, it was all on me. Having your parents paying for your education does add an additional stressor to the whole situation. Would it be possible to take a few courses on a part-time basis, while you continue to work in order to see how you like this new field before your commit time & resources to full-time study?
Personally, I just wouldn't worry about the age difference. I don't know how things are in the Netherlands. But here in the U.S. there are always people of all different ages taking classes. And individuals, for the most part, just gradually find other students who are in similar circumstances to themselves, & they band together. I would surmise that you would be able to do the same. Good luck!