The hard part about making music is its creation - once it exists, it is easily distributed.
Therefore, everyone has access to the "best" (defined by a combination of popular preference and industry mandate) music available.
Furthermore, a LOT of people want to make music professionaly - its fun, and it gets you a lot of positive attention. Though it may feel difficult and high-pressure, it really isn't - compare it to being a tech at a nuclear plant or a surgeon - THOSE are high-pressure jobs. If you've got to do SOMEthing for a living, music sounds like a really nice option.
So, there are a whole lot of aspiring musicians, but most listeners listen to just a few musicians.
What this means, is that you've got to be extremely good and/or extremely lucky to make any money publishing your music. It's like playing the lottery - you've got low odds of a great payout. If you happen to win, congratulations, but you have no realistic excuse to be irritated when you don't.
If you really want to make money as a musician, consider playing live. It may not pay well, but your odds at getting some actual, steady income from music are FAR greater.
This is far more of a personal opinion, but if I were you, I'd remove all mention of not having a degree/certification in music - it comes across as putting yourself down, and there's no reason for it (at least in American culture - if perceptions are different in your part of the world, please correct me).
