Hi there! I'm also live abroad, and the ex-pat crowd down here also sticks to bars (yes, there are Irish Pubs in Central America). It can be frustrating watching others who are in your situation go out to the bars, come home and hook up, and then watch them the next morning at brunch hashing over their crazy nights.
But face it, we've been there and done that already. Right? What more can we gain from a night at the bars? The first thing to do might be to stop imagining all the fun that others are having. Whoop-dee-doo, they went out and got smashed and made out with other tourists and slept on the floor at a hostel and then stumbled home at 5.48am. They are lame and immature, not cool. Don't worry about them and their dumb hobbies.
Being sober, you can really get the most out of your experience. Living abroad is great because of the travel! If you're in Lux, I'm guessing you can take a train to some cool Euro cities on the weekends, and perhaps see some great sights in your own cities nearby as well. History, museums, culture, and CAFES abound. I have made some great connections in cafes. In fact, I am meeting out with a new friend of the opposite sex in a few days, we met last week at a cafe and said "let's do it again!". Or take a language class! Those are great for meeting cool guys and gals. What about outdoor activities? Hiking, climbing, skiing? Go to the lake or the river for a swim. You won't meet people who are doing sober activities unless you go to those places because that's where they are!
Good luck, you can do it.