Excellent comment. I'm one of those people who always thought: "I can't draw". Now I understand that for me it is a matter of practice. I started with Drawing on the Right Side of the Brain.
The thing with a lot of the arts is they aren't pushed or required in school the same way math or writing are. So someone that says "I draw like a five year old" probably stopped drawing around that time.
I'm a firm believer that everyone can learn the craft part of drawing and painting. Some people will learn at a faster rate and some will learn at a slower rate, but everyone can learn. And just like math and writing, there will be those who excel, those who are average, and those who are below average.
I was trained in singing in elementary school and then again in high school.
I made an honor choir or two. (This would be a significant accomplishment if I was female, which I am not. They'll take pretty much any boy who can hit the right notes.)
Years ago I recovered from a cold except that the phlegm in my throat didn't go away. It is still with me. If I try to sing, my voice will just cut out on certain pitches, and sometimes I'll get a gurgling effect from the phlegm.
I had a voice teacher who was also an opera singer, and "singing when you have a cold" was a very common problem for him. Every singer has to do it, so I'd encourage you to consult one. Good luck.