I’m also an artist and also a university student so I completely understand your feelings.
At first I also was surprised but then I realized that a lot of of people who ask for free arts are financially incapable. Most of them are still underage students so spending money on a art is difficult for them while they are still dependent on their family’s finances.
However, that does not mean artists like us cannot be able to do the things we deserve!
The cost of effort and time for our arts can exceed a person’s spending, but that cannot make our arts any less valuable!
For these reasons, nothing can stop a talented artist like you open commissions 
Don’t worry, be confident with your decision! 
To tell you more about free arts. Honestly, sometimes I do art for free because of my passion for drawing and to practice to get more experience. if I have free time, I will draw for free for some authors who have great stories but not many readers know yet. However, the number of art requests are always much 
The people who ask for free arts are always a lot. Some people require their details so elaborate that I don’t think I can do them for free anymore!