Try to find things to keep you enthused while you still have to be there, like clubs/societies, especially if they're in fields that you're not too comfortable with at the moment. For example (I don't know if this will apply to you, since your post is quite articulate), I went into the debating society in high school with very little knowledge of public speaking and a lot of nerves about presenting in front of people. Two years later I was competing at the national level, and people still think I'm a good speaker when I just wing presentations without preparation. You have a lot of free time right now (maybe it doesn't feel that way, but it's a lot compared to what you'll have later!), so make use of it in a way that pushes your boundaries and expands your skills.