Take care of yourself first. Nothing wrong with getting a "prize" for your hard work, and/or a gift to make you feel good if you truly can afford it and desire it.
Charity is nice, but if you worked hard, I assume you did so for the sake of bettering yourself, not for others.
Having "so much" or more than the next guy is just natural order. There is a curve that everyone falls upon. Some of it is fate, some luck, health, chemistry, intelligence, some of it is fair, same of it may not be. You fall where you do, and you can climb up a bit, or fall back a bit depending upon our decisions. In this day we are supposed to "celebrate" everything. Every race, creed, diversity, culture, sexuality, and whatever else. How about celebrating the sweat of your brow?
It is one thing to wear flashy clothes, jewelery, and drive around in an escalade with big wheels and obnoxious sound to "flaunt" what you have to the next guy... and prove superiority through material means. It is another to buy yourself something because you've worked for it and can sustainably acquire it from your effort, frugality, etc.