[vmception]

As others said, try to take leave but there is a reality where that is not possible:

This happened to one of my parents at the beginning of my career but I was a contractor and had to make ends meet in the new city I had just moved to. My parents were of the position that they raised me to do that specific thing and wanted me to do that. As far as focus, this wasn't difficult for me except when there was news. More than a couple times I did have to abruptly leave one city and transit to the other where my parent was in the hospital. There was no certainty about my job but that part did work out for me, but it just as easily could have not. For me, the separation allowed for more rationale prognosis because the original diagnosis was obviously a death sentence (your situation may be different and it wasnt specified in your post) and both me and my afflicted parent understood that pragmatically, but the people there through the whole process stuck with the hopium that a miracle would happen. They couldnt see the subtle deterioration day by day, but me being there every 3 weeks made the snapshots much more obvious. “Yeah spot on diagnosis doctor and the entire internet and all studies that omit how the few percent that do make the 5 year survival rate are not having a good time”. I think its easier to focus when being practical, like you dont need to be a nihilist to the people around you during the process but it is possible to skip all the stages of grief and accept it while keeping a positive outlook. Its not like the people that didn't beat cancer weren't strong enough, its just that a random direction of metastasis disrupted a crucial life process or not. So the stages of grief will be the most distracting if reality will not be accepted, but you can steer the energy positively without distorting reality.