I feel for you, Joe. I've been there. Waiting for the health system to move, when all you want is to know if your mum will be alright now, is torturous. My suggestion is to concentrate on being a support for your mum, who's probably experiencing all kinds of anxieties and fears herself. She could need to express them - or she might just appreciate your company to keep her mind off it all. There will also be practical things she needs your help with as she prepares to go to hospital and when she comes home.
At the same time, look after yourself. If you're anything like me you could feel a powerful need to talk about all your worries with someone. I seem to remember you have a boyfriend, or you might want to see if there's a UK equivalent of the Australian Cancer Council, which provides information and support services.
Finally, they don't know if it is cancer yet. I truly hope for the best outcome, Joe. Whatever happens, we'll all be here on The Haven if you need us.