It varies because I'm also a carer for my husband and that takes priority. Sometimes I can write for two hours in the morning, sometimes I reserve a couple of hours in the evening. I set a limit of 2000 words a day - it can be a struggle and at times music helps. But I also take time to read and see what people are saying about other books and authors. Even if you're isolated as many of us are now, by Covid and the need to shield someone, it's important to stay in touch. I start by re-reading what I wrote the day before, and put myself back 'in the world'. When I'm there, I can see where the story needs to go next. I do have a project plan and character descriptions of course, plus the details of the worlds I'm in - geography, relations with other places, plants, animals, climate, and anything special that needs its own life-story, such as Chass or Pirrix animals.
Yes, often, sometimes for a day and the worst was when something really bad happened in my life and I 'dried up'. All I can say for the latter case is that it takes time and I did try each day, to sit down and put something - anything - on paper. I wrote short stories and poetry in that period. It's important to keep going, and keep the faith in you, your work and your goal. They say 'imposter syndrome' can cause a block or result from it. But I believe blocks are there to be dealt with; they're not symptoms of inspiration drying up, just rocks in the path. Keep hammering away. You can do it. Go for walks, do stuff you like, listen to music, dance, help someone. It's amazing how taking the focus away from the problem can make it lessen.
A lot. You need to have the determination to do this and do it well. And you need, at least I need, to be organised and know where to go for help. And always back up your files. Yes, I know you all do that. But in my case I nearly lost an entire chapter and now I'm a backup convert. Publication made me re-assess how I spend my writing time too. We're lucky that long-published writers are so generous with their time and advice. There's a plethora of good resources out there, and when you've gone through the process of developing your story through to publication then you can look back and see a lot more clearly where the important milestones are, and how to plan better next time. I bought 'Scrivener' because of my science background that makes me think, 'plan this properly' and because the software offers a lot of good options for book creation. I write in Word and use its functions too. It's just the way I do it. You can do exactly the same with paper and pen. It just takes a lot of paper, filing, and organisation. Going back to the question, I learned from the experience, and I hope to put those lessons into practice.
I only wish I knew more about what makes a story readable. I'm a first timer in fiction publishing but I do realise we're in the business of selling our story and our vision to readers. And we keep our readers in mind from A to Z when creating the story. All the people I've spoken to about writing, from authors I've read, from workshops, online and YouTube tutorials emphasise that. It applies from the initial setting, the plot, characters and their development to sentence structure, word choices and theme. For me, the underlying foundation of good writing is the good sentence. It should be clear, focused and make a contribution to the narrative. I cut more than I keep and although that hurts, I learn from it. Editing is a valuable skill and although good editing is the province of the professional I try to apply as much as I can of the principles when I re-write. Its part of the attraction of writing - learning the craft every day.
Huge sympathy goes to anyone experiencing that. It's frustrating and in the family context, can be especially harmful. I joined a writers' circle early on, and found good companionship with people keen to learn more about, and talk about, writing. It does make you feel good to be part of a group, whether online or in person when permitted by the bug. Good groups encourage their new members and their ambitions, and a wise choice can help you when you're feeling like nothing's going right. The calming and soothing effect of music is well known. I use a few good 'ambient' music tracks when writing. It's something to do with the effect on brain wave rhythm and the creative side of the brain. Exercise is a must if you're a full time writer. They all tell us that, and I do try and exercise regularly. Part of my career was spent peering down a microscope and part locked onto a PC, so I do appreciate how the body muscles can feel. A stressed body is not what you need if you're feeling emotional stress too. So yoga and walking, swimming and a few 'Mum dances' are a part of the writing routine. And if you're nervous about putting your writing in front of an agent or editor, a writers' group can help and reassure you by being readers or beta-readers (as long as you're able to respond in kind or other thank-you). Dealing with stress caused by rejection is a huge topic, All I can say is that no-one's immune and we all share it.