Can I just say- you've only had two weeks of university, people won't have settled into friendship groups.
University isn't like school and friendships groups change around/expand a lot at university.
People are more open-minded at university and it's definitely much less cliquey than at school, so don't worry about not having a group of friends after two weeks.
I remember clearly a talk that was given to us during Freshers Week. We were told that we wouldn't even talk to whoever we were sitting next to at that particular moment ie "our friends" come the end of university. They were pretty much right :P
Also, although other people may not look like they are struggling, many will be. Many other students will secretly be making late night calls to their parents, feeling homesick, wondering if they have made the right decision by going to uni, worrying if they've chosen the wrong course etc
It will get better though and don't beat yourself up about it. Making the transition from school to university isn't meant to be a doddle, everything is so different, but it will all come together in the end.
It may be worth visiting your university counselling centre or well-being centre because there are experts there with whom you can discuss your concerns. It is free and confidential and will probably help you feel less anxious.
Perhaps try just one of the societies that you like the look of because you will probably meet some people there who will become good friends