My opinion is that the most difficult part of writing is creating enough stability in your own life to want to write.
Find spaces and times where you become relaxed enough to introspect and soon you will be able to build very real spaces and events in your mind's eye.
In this mind space you get to think of yourself as a game-designer with no budget, where first, the map must be created to give thematic context and draw outer bounds on the action. In short, world building. Then the world must be populated with characters who you expect to be in certain locations, who will live in particular cycles and react to particular other characters in specific ways. By the end of writing a book, you will be able to picture the geography of all the groups who drive the conflict of your plot.
Unfortunately, just like the characters in our stories, real life is filled with events that "drive the plot forward" and essentially, introduce antagonism into our lives.
Navigating these events for ourselves inherently gives texture to our writing because we learn what people really do in the moment of an event. However, the downside is that you must live that event all the same and usually we make at least some small mistake we regret in any given encounter (and often a big one).
As a side-note, I recommend applying this to your written characters. Rarely allow them to make a fully positive or negative decision or risk creating a sense of surreality.
Returning to the topic of creating stability, I want to clarify that I do not mean achieving outright success in every aspect of your life. What I mean is that you attempt to balance your emotional budget. Sometimes we have to cut costs in areas we cannot afford.
Anything we routinely get angry at is an example of a recurring cost in our emotional budget, and, although I don't know your situation, I recommend learning to live in peace with it. An easy example many might experience is coming to peace with a spouse or friend who has differing religious or political leanings.
In my case, I will admit there were times where I felt as though I needed to convince everyone of evolution. In hindsight I could have removed the stress from my emotional budget a long time ago because it isn't effecting my day to day life and it's more valuable for me to have good working relationships with coworkers.
Cutting out these reflexive reactions I have to different people and ideas has to be a part of everyone's journey as a writer. In addition to the clear benefit of gaining a wider understanding, cooling our heels about prejudices allows us the mental clarity to be productive and feel good about sitting down and creating content.