I try to get social media and email out of the way first thing in the morning with a cup of black coffee! Then, exercises, and I clean off the top of my desk and then get to writing on my laptop. I usually have classical music or even ocean sounds playing in the background.
I don't think there's an author out there who doesn't do this from time to time. That's the beauty of writing fiction - you can use a good or bad experience from your background and make it fit in your novel just the way you want it to.
I'm fortunate that has rarely been a problem for me! I try to research my subject (or time period, or location) as best I can *before* sitting down to write about it. This probably stems from my years as a travel & lifestyle journalist.
Don't over-write. I remember being taught years ago by a very successful travel journalist who said that when writing a travel article, no one cares what you ate for breakfast. Similarly, don't be over-descriptive or think you have to use flowery language. Good writing is much more about readability.
It can be the loneliest profession in the world and you can be full of self-doubt and/or be a procrastinator. But you have to start somewhere and defy all the odds! Just do it. Just write, and get the best editor you can afford. They're like gold.