Wow, it's horrible being stuck in a morose mood, isn't it?
First, if you have any kind of storytelling aspirations, before you do anything else take a second to capture this emotion so you can use it in your writing and scenario design; jot down notes on what you're feeling. Did Queen Zeal feel these same fears, and that's what drove her and her fellow Zealians to search for immortality, for example?
None of us are immune from musings on life's mortal coil. But one can survive death by leaving a positive mark upon the world: that is the nature of human progress. If you're able to create something, you can achieve a sort of immortality. This is one of the meanings of art for me. As Uboa said, you also carry a bit of your relatives with you if you remember them, and through you, they achieve a sort of immortality.
Also, real-life reincarnation isn't out of the question any longer. I fully intend to get my brain frozen and revived in some future era, because I've been spoiled by being born into this era of fledgling technology, and I can't stand the thought of not knowing what heights humanity will reach in the distant future. What pisses me off right now is that story where an Alcor employee
threw a wrench at Ted Williams' frozen head. So, yeah...maybe this isn't for everyone. If what's in that book is true, it's an affront to all human aspiration. But scientists have become the gods of old, making the blind see and creating lighting (EDIT: Meant to say "lightning" there, but...yeah, Thomas Edison did a Biblical thing there). Control over life and death should be just as possible.
And as others would point out in response to my banking on science for physical reincarnation, we haven't solved the mind/body dichotomy yet. I don't pretend for a second that heaven and hell really play out exactly as told in typical religious fashion, but there could be some other element to our existence we haven't scientifically measured yet. Perhaps it's forward of me to suspect something's out there for which I have no physical proof, but on the other hand it would be forward and dull of us to suspect we've already uncovered and measured everything that can be uncovered and measured.
Getting back to the subject of life: Your coding skills, should you choose to continue developing them, could become a major artistic asset for you in the future. When I was your age I was flirting with developing those very skills, but chose not to, and now that I've rethought my life I'm partly kicking myself for it, and need to make up for lost time.
On the other hand, you may also want to take account of what, exactly, makes you happy. Like, truly, deeply happy and fulfilled. Something that doesn't feel like "work" even though you put a ton of effort into it. Once you're in the dream phase of your life, you should be able to spring out of bed actually looking forward to the day unless there's some major catastrophe happening.
And Happy Birthday!
PS: Mr Bekkler, really sorry to hear about your older sister. That would have been a huge psychological blow to me at that age, and reflecting on this makes me really appreciate just how well I've had it.