Keep your day job and do it anyway. Artists of all kinds must work at their trade. Sure there are some exceptions where people are just born with skill, alas even they are not perfect. In every walk of life, you face someone that is better than you at something, or maybe you are better than them, so it goes.
If you want to write, write.
Most of us write because there is just a driving force inside of us that compels us to. Sure you can ignore it; I did for twenty years. However, it eats away at you and makes you miserable, and that trickles into everything else you do in life, and onto your loved ones.
Write, or sing ,or draw, because it's your dream. Even if it's just for you - do it, for your peace of mind - do it, for your families happiness - do it.
For instance, right now I am a bit sleepy, it was a rough week. I kind of think a nap is in order, and yet here I am typing away and thinking of what I have to do once I hit publish on the blog. Because I know I only have two days off work and its back to the daily grind. So I push through, this is so much more fulfilling to me then a nap will ever be.
If you are serious about your craft, work at it, practice, learn and get better. You may not be the next J.K Rowling, or Stephen King (I think he is the most used reference in writing) or even have a one hit wonder like E.L. James, but it is you and yours; and no one, not even your worst critic - and trust me you will get them - can take that away from you.
We can't all be the top dogs, or the rock stars, or the literary geniuses, everyone needs a waitress and a gas station attendant. So don't fret you are still a part of the cog in the grand machine. Spin your tale and keep the wheel greased. Have fun, be you and never give up.
Happy Writing, Theresa.