Hopefully it's worthwhile, because it's what I want to do as well.
Depends really on why you want it, and what you'd settle for.
If you decide you'd like to write the next big sensation and make millions, that's probably unlikely, and a bad reason to get into writing, but you probably know that!
If it's for the creativity, and the sense of creating something, then it's worthwhile writing for the sake of writing.
I have a load of half finished stories, they tend to turn out not as well as the rough idea that starts them off, and I get disillusioned. When it goes well though, it feels fantastic, creating my own little world in a way that's really fun - and if I could get it right more consistently, that'd be amazing.
Being able to write professionally - spending the whole day writing things I feel proud of and that I know people look forward to reading, would be absolutely amazing, and my dream.
From my knowledge of the writing industry, a lot of writers earn either their main money or side money as teachers and journalists, or reviewing new books/films etc. amongst other things.
It might not be possible to get the exact dream version of being a novelist that you want from life, but with enough hard work, you can probably get something close.