What I do and is working for me, is I usually write when I am inspired. I tried to write every day, but this technique does not work for me. I usually write phrases to be used in the future, but when I am inspired, I write a story from be beginning to the end. I do not worry about grammar or how well constructed the sentences ar. I write and write until I reach the end. Then the cleaning of the writing takes place days later. You have to find the technique that works best for you. If you are stuck, leave it alone. Inspiration will come at the right time. Sometimes I start writing about a particular topic, I get stuck like you. I move to another story, and I come back to my previous writing when I am relaxed. Sometimes, I write without thinkning or worring about anything. This has helped me to find inspiration deep inside of me. Always write taking in consideration how would you approach a particular situation/issue. This also will help you focus more. Write the beginning and the end. The in between will come along the way.