My dream when I was a young 'un was to be a writer, and I guess I’ve managed to make that a reality in one form or another. I wrote (appalling) fiction as a teenager and some (passable - won a couple of prizes) poetry at university, but always understood it would be practically impossible to make a living from that (I kind of wished I’d been in the US where writing MFAs are more of a thing - but c’est la vie). So I stared doing stuff for the student newspaper as well, reviews and interviews and columns, then got a job as a reporter on a local paper, then a trade magazine, then moved into marketing and doing copywriting. So I’ve always made a living from writing, even though it’s not the glamorous side of things.
As for writing for pleasure / creative writing, it’s nearly all been focused into doing my blog, which has been popular enough for me to keep it up - I’ve been nominated for some awards, get sent freebies, been offered paid work off the back of it. Outside of NaNoWriMo, I haven’t really done any fiction for a long time, even though I really enjoyed it when I did it.
I don’t know what I’d suggest for getting over fear of embarrassment of failure. I guess I have quite a lot of self-belief - if I thought it was crap, I wouldn’t do it - but I’m aware of my shortcomings too. But ultimately, you just have to write, get stuff down, anything, no matter how crap, because you have to start somewhere. And over time you’ll start to realise which bits are crap and which bits you’re proud of and you’ll start to do more of the latter.