Novel Writing: How Do You All Do It?

So I've been writing the same novel for three years.

It's very short and I hate most of it. I find that writing longer form works (ie longer than what I post on here) is a super super emotional and draining experience. How do authors pump out new books every year or two? How do they not leave it for two days, come back and realise they hate it all and have to start again?

I have a feeling that if I ever finish this novel and publish it, it'll probably be the only book I ever write. I feel like I've poured every ounce of myself in to it, and I have nothing left to give. That's super dangerous, too, because what if everyone hates it? I don't think I could handle that.

Has anyone ever written a long story before, in whatever form you've put it in? How did you keep up motivation and energy, or balance your time?

For now, here's a piece of music I've rediscovered recently. I played this album to death about six years ago and haven't had the heart to hear it again until recently - it's like meeting an old friend again after a long long separation.

xx B