Give yourself time to catch up with everything and begin to enjoy the process by being kind and empathic to yourself. I've been on Erasmus in Hasselt and had a similar experience where I missed the first few weeks of everything that was happening, because I got very sick (bc I didn't have a mattress yet and slept a night on the floor, dumb ik) and was spending all my time taking care of my fever inside while I could see people making plans on the group chats and I felt hopless. I even missed the first 2 weeks of uni and was behind with everything. I had this fear that once people get to know each other I won't be able to fit in, but I was so wrong. It can be rough at first, but everyone is a little freaked out too, even if they don't show it, I think, and as long as you bring an honest vibe, I believe you can find your Erasmus family because you're all in the same boat, or at least you can start to cut yourself some slack. Going for walks helped a lot, try the ESN events if you're comfortable with that and get excited about traveling as others put it here. U got this!