Everyone is sharing tactical solutions, which is great, but I've found that the root of the problem lies in not knowing your values, and I wish I was introduced to this concept at your age.
I learned about this in an excellent book called "10 Natural Laws of Successful Time and Life Management" by Hyrum Smith, the creator of the Franklin Day Planner.
It recommends that you write your own Personal Constitution; much like the United States has a Constitution written by the Founding Fathers that guides the creation of future laws, you should create a Personal Constitution that guides your future behavior.
It's essentially a prioritized list of what you hold most dear. Then whenever you need to make a decision, you act based on that list. Of course, you may choose to amend it at any time, so it's not a static document.
The process of creating your Personal Constitution is a difficult one so be prepared to set aside a few hours to really think things over. But the exercise is utterly priceless, as you'll have extraordinary clarity of mind and a rock solid decision making framework that allows you to focus on the things you most cherish.
Stephen Covey wrote a book along these same lines, First Things First [1], which advises to first define your roles in life, such as developer, parents, home owner, and so on, then identify the priorities in each of those areas, and schedule those things into your week first. He gives the "importance/urgency" matrix which is helpful for identifying which things you should be focusing on. After you have scheduled the important things into your week, you can schedule the unimportant items.
Having said that, you still have to make choices and stick to them. For this, you need to look at the science of habit change, which a good book is The Power of Habit [2]
I learned about this in an excellent book called "10 Natural Laws of Successful Time and Life Management" by Hyrum Smith, the creator of the Franklin Day Planner.
It recommends that you write your own Personal Constitution; much like the United States has a Constitution written by the Founding Fathers that guides the creation of future laws, you should create a Personal Constitution that guides your future behavior.
It's essentially a prioritized list of what you hold most dear. Then whenever you need to make a decision, you act based on that list. Of course, you may choose to amend it at any time, so it's not a static document.
The process of creating your Personal Constitution is a difficult one so be prepared to set aside a few hours to really think things over. But the exercise is utterly priceless, as you'll have extraordinary clarity of mind and a rock solid decision making framework that allows you to focus on the things you most cherish.
Give it a shot!