1.5 hours is like Eindhoven to Amsterdam, IE: from one end of the country to the other... really not bad (IE: trains are fun, have wifi, etc) but I'm wondering here if part of the problem is that you are far away from where you might have more connections?
Either way, whether you are in some tiny village or the big city, get out of your flat and down the street - to the pub, the gym, the church, etc. Whatever your thing and whoever your people are, they are out there somewhere and it's just a matter of figuring out where to find them. Yes you have to put yourself out there and that can be hard (I'm horribly shy and introverted myself) but that's the cost to connect. I'm wondering - even though Dutch people are wonderfully poly-linguistic, I'm gathering that you might be foreign and I'm wondering if you are concerned about your language skills? Is that feeling like a barrier for you? Best way to improve on that is get out and start interacting.