We just have to keep practising and realising that every moment is precious, and so are we. Not wonderful perhaps, but precious, and human, and as Maezumi Roshi said, ‘Living the unsurpassed life.’
It’s not a matter of intellectually figuring out what mu is. To see muji you must put yourself completely into it until you are mu itself. Concentrate on muji until you and muji become one thing, and then keep on working.