First, don't stress out too much, because you'd be surprised (as has already been manifested) how many people feel this way when they leave home for the first time, or when all of a sudden they're out of their parent's reach and all of a sudden find a lot of independence. Everyone abuses independence at first, whether they turn into total party animals or they feel lonely and uncomfortable. You will make a few mistakes during the next couple years, but guess what? That's totally okay, and you will be able to put them aside as learning experiences.
Second, I agree with the comments above about doing things for YOU and getting to know yourself and your passions. Honestly, since you've moved away, most of the people you knew in high school will become distant memories. You won't talk as much anymore, and you'll make new friends. This cycle will continue. You may keep in touch with a few, but the majority will move on as well. So don't be too broken up over it, but realize that there are a lot of great people out there to make new friendships/relationships with. But, because people are often fleeting, that's why you need to focus on yourself and who you really are and what you want out of life. Maybe you will learn that the lifestyle your parents wanted for you is NOT what you want, or maybe you will learn that it is.
Ultimately, you're young and at a prime age, and you've got so many great opportunities ahead of you, so don't worry at all, as the feelings you're experiencing are completely normal!
