Keep in mind this is based on my personal and technically also religious beliefs.
Continue on the path of being a scientist. Start keeping journals of things, especially world events. Learn things, and collect things to sell when they're older to make money. Stocks and other investments. Build myself a fortune but be a recluse and act like its my heir taking over every so often. Be incredibly upset as people I love get old and die. See the world, experience things, write about them in said journals. Potentially publish books, either as fiction or nonfiction (like hell the government is getting ahold of me, I'd have to be careful). Learn how to take care of myself with the essentials, even while living comfortably. Be upset when the human race inevitably destroys itself, potentially leaving me as the last remainder of humanity. Survive as evolution occurs again, watch the new race, potentially be regarded as a god. The sun will eventually go supernova, destroying the planet, hopefully also me, since there shouldn't be anything left to regenerate me.
If I were ever tired of existence I would probably shoot myself in a rocket into the sun. While it may not destroy me, I will at least not be conscious as my body is continually destroyed and reformed.
Also, off topic, I don't know what to do about my captcha. The second word is literally the symbol for sigma, 'o', a carat, 'e', and a line that looks like it might be part of an r with the curve removed. THAT IS NOT A THING. I DON'T EVEN HAVE THE KEYBOARD TO TYPE THAT. EDIT: HA HA HA HA it actually took the first word and 'sigmaocarateline' as the second.