I'm guessing finding a new job in a different town isn't an option?
The town I city I grew up in (pop. 47,000) isn't so small that I couldn't meet new people, but the Dutch are naturally reticent and reserved and unlike the Boyfriend, I am not the sort of person who goes into a room and just starts chatting to everyone. I met new people through volunteer work and hobbies (do you play an instrument? Because a band or orchestra of some sort is a great way to meet people).
(The Boyfriend's hobby is to walk into a room full of strangers and see how many people he can meet by the end of the night).
You write that not everyone around you is old, but they are married or engaged, they have children, and they are 'boring'. Are you specifically looking for a boyfriend/husband relationship? If so, turn to the internet. Is it a perfect replacement of social contacts IRL? No. But it does help a little.
If you're not specifically looking for a boyfriend, well, maybe you could start your own club? Book club, band, orchestra, film club, gardening club, cycling/running club... At least you'll be around people.
I can't offer you any more advice than that, but I've seen the small towns near the city where I live where everyone knows everyone and there's exactly one church and a community hall and that's the extent of the social life there, and I dread living there, so you do have my sympathies.