Wait, Gareth is DynamiteKid? It's all making sense now. Also welcome back, Jens, it's kind of funny how we returned almost at the same time.
As to your social uni problems, that's exactly what happened to me to when I first moved to Glasgow. I tried to hang out with everyone and go clubbing every week despite being way out of my comfort zone, which after a couple of way too social weeks eventually ended up with me declining invitations more and more often until I stopped getting invited and I was back to being my usual hermit self. Don't worry, there are other hermits who will enjoy your quiet company, just don't try to be something you're not. The clubbers in my school still go out every week three years later, and I don't really have anything in common with them, so why bother.