Hi, and thanks for writing with this question. I actually felt very similar to you at your age. I can’t recommend anything specific to you (or anyone) because we are all different and need different things. However, I think I can give you some thoughts relating to what’s happening and how you can pull through to be happier and more Independent.
First of all, it’s okay to feel like you don’t connect with people at your University. Schools like this tend to give the illusion that everyone is out there, energetic, and extroverted. That’s simply not the case. Those are the people you see, because they are so outward, loud, and social about it. I think there are just as many people like you, feeling the way you are feeling. It’s tough finding them, but those are the people you need to connect with. I would definitely be honest with yourself when you look at these social pressures. If it doesn’t feel right to you, back off and find something that does feel right.
College/school can be very difficult when you just want to grow up and be independent. I felt the same way. It may be helpful to spend some time with that feeling and let go of this notion of “missing your fun teenage years”. You can’t miss something that isn’t fun for you. People always told me what to do when I was around 18. They said I should get out and party, get away from family, get away from childhood friends, live in a certain way… These things may have felt right for them, but they did not feel right for me. I am so glad that I was able to look at myself honestly and have the courage to say, “No, I’m going to do something different.” In the end, I was true to myself and I am very thankful for that.
Instead of looking at yourself and feeling like “there’s something wrong with me for feeling this way,” why don’t you look at yourself and think, “I need to find people like ME!” Start with your interests. Don’t look in places that you wouldn’t go. Maybe join a group of students who may also feel like growing up and becoming more independent. You’ll have more luck there than at a party, where most people want to stay young forever.
As far as becoming more independent. I would embrace that. Become more independent now! I have known people who started businesses while in University and others who began crafting a skill or hobby that would become a huge part of their adult life. What do you like to do when you’re alone? There’s no right or wrong way to live as an introverted 18-year old. You have to decide how to live on your own. Find an ideal friend in yourself. That’s the best (and first) step to attract more people to emphasize who you are and make you happy.
I would also recommend reading up on being introverted. It sounds like that’s what you are dealing with. I am an introvert as well. Here are two comics that spoke to me. One by Luchie and another by RomanJones. You could also read the novel FanGirl by Rainbow Rowell. I am 2/3 done with it right now and the main character is your age and feeling almost exactly the same. It’s a very good book. Highly recommended, especially for you. Oh, and another recommendation would be Quiet: The Power of Introverts in a World that Can’t Stop Talking by Susan Cain. Hopefully that will help you.