You (yes you) have so much ahead of you. You're going to be experiencing things that you wouldn't imagine or expect. There are many accomplishments, journeys and good times ahead. Just think about all you're going to learn, all you're going to share, and all you're going to see. It's going to be great.
How do I know this? Because you're made for it. You were not made to be bottled up, hidden, or alone. Even if you think you are, I would encourage you to do one small thing at a time to come out of that. I'm not just talking about being shy. You don't have to be shy to be hidden. On the contrary, you don't have to be outgoing to be hidden.
How we think determines how we act. (And vice versa.) But, if you don't think you can do it, you won't. If you don't think you ever will, you won't. If you're not going to tell yourself that you can, I will. I'll tell you over and over again until it starts to sink in because the absolute truth is that you are made to do more.
Don't let guilt take that away from you because it should be freeing. Just think about everything that's waiting for you. Visualize it. Dream about it. Make sure those ideas are crystal clear because if you think about it long enough, you'll start walking. Eventually, you might end up looking back and asking yourself what the heck happened. That's real dedication, which, by the way, isn't so hard when you're focused on the end goal.