I'm not one of the highly-valued but it does happen.
I think writer's block is just part of the job. I deliberately decided when I started writing stories not to do it for money, 'cos I didn't want the pressure/hassle.
What I do is just accept it and do something else; walk the cat, go shopping, cook a meal, watch telly, read someone else's stories. If I'm really, really desperate; do my actual paid job!
I'm a great believer in "Attention without Deliberation" Your conscious mind is not thinking about it, but your unconscious mind is. And suddenly it will pop up when you least expect it going "Hey I've got an idea"! Have a word processor on your phone so you can jot ideas down when they hit, and they will hit.
Good Luck!