Honestly - it is stressful, and every manuscript goes through a phase where I want to burn it, but just keep pushing through. If you can't write due to stress in your life - that is okay, go with it and come back when you are able and ready. Also hydrate, take your vitamins, get the sleep you need, being physically well helps the creative brain bloom, vs overtired and sick.. So if you can stay healthy, that will help a bit.
When someone messages me or writes me to tell me that my book has made them feel something, or realize something, or heal from something. I count those as major successes.
I think most writers have dealt with the dreaded Writer's Block - my best advice is to keep writing. Perhaps on a different story, or perhaps a different style or genre. Keep writing, and make sure you are getting enough water, sunshine, and sleep. All of that helps (although the sunshine part is debatable - I feel most of us writers live in the dungeon of our offices/writing spots and rarely see the light of day..hahaha)
Oh yes, many times. Real places, people, things - often disguised, but very real. They do say truth is stranger than fiction - and I have found that to be true - so I fictionalize it to protect the innocent, but definitely included it. :)