Hi Alex,
I started collecting when I was 7. I'm now 43; married, two kids, a growing business to run - essentially more responsibilties than I have ever had. At least partially because of my busy life, I enjoy the hobby more than ever - it's a great escape from the daily grind!
I've have had several times when I stepped away from the hobby for a break - most of high school, college and my early days starting a career. I would not advise selling any cards at your age unless you are in a cash crunch. I cannot tell you how happy I am that I kept my cards. If you are as into the hobby as it sounds, you'll most likely be active again in the hobby thoughout your life. Set them aside take a break if and when you need one.
Keep balance and perspective, there are times when you have to miss an auction or show because you have other responsibilities. I can guarantee you, there will always be more! Hopefully this rambling post helps you somehow.
