I started a business around the same age as well. I learned far more from my business during that time than spending that time in a classroom.
When you ask people for opinions or help in making decisions always remember that you're going to receive many different answers from many different people.
The best advice I can give is follow your gut. Go with what you think is best, even if someone you trust and highly respect gives you their opinion which differs from yours. In the end, you will have to make the decision and carry that burden. Never doubt yourself.
You will always be faced with new obstacles and challenges. Never let them stop you. Obstacles just require additional thinking about how to overcome them.
At first I had a really tough time delegating tasks to other people, especially if I thought I could do them better. However it is really important to learn to let go and to let other people do things so that you can focus on what you do best.
Remember that there is a difference between working on your business and working in your business. If you are working in your business, that time is not being spent on building your business, that time is being spent on keeping your business going as it currently is. Do not get stuck on working in your business, do both!
I wish you good fortune and many adventures in your new business.