Start the work to silence the doubts.
It’s never going to be an optimal or easy time to start a work in progress. And perhaps that is the best thing! Sometimes it is the outside agitation that makes for the best writing!
Writing is one of those careers or hobbies that can be done any or everywhere! A work can be started at any time. It can be paused and restarted and changed as you deem fit.
But you must start it.
You must start.