Remember what you’re working towards.
You need to submit your thesis, but you’re not working towards that. You need to prepare for your viva, but the work isn’t for the sake of preparation. And you want to pass your viva, but that’s not what the work is for.
You’re working towards BEING a PhD. Doctor Someone, with a doctorate in something special.
Whatever stage you’re at – submission, prep or the day before your viva – you can only get that far by working and building yourself into a PhD.
The work helps you succeed at whatever stage you’re at, but also moves you closer to the end result.