I FEEL USED UP AT 19 YEARS OLD?

If you haven't sought help from a professional, or just don't want to, there are limited things you can do. The first thing would to be vary things up a little and try new things. Even if it's something as simple as trawling youtube for new artists. Another would be to try some home remedies. St. John's Wort is an herbal remedy for depression, for seasonal affective disorder I've heard that some people go tanning. Vitamin D supplements might help too. I'd really suggest seeking professional help, at least to see if you might have seasonal affective disorder.