How can we stop grieving a very unfortunate diagnosis?

The person is not dead yet of course and we don't know how bad it is or what treatment will follow. However her life has changed and needs assistance. Losing one's own independence within just a month takes a lot of courage. And the caregivers must be ready for any possible scenario. However it's still too early and life must go own. Things for sure cannot get better but I don't want to stop enjoying life waiting for it to get worse and worse.