accepting the impermanence of loved ones?

My mother and I have slight issues because she is nagging and controlling (and I impatient). Despite that I love her very much, and I can't stand the idea that she will pass away in a few years; and she will suffer during death and later in a lower rebirth. I start crying every time this comes to my mind. In the moment I feel like leaving my job to go live with her and serve her (*I live in a far foreign country so I see her once a year or so*). Further I think of accepting it as part of life, but nothing comes to mind. I wonder, how is it even possible to be okay with this? Is there no other way but to endure great suffering when it inevitably happens? I wonder how other people deal with this? Do they all go through intense pain or somehow skillfully avoid it (especially buddhist master's who are not affected by this at all)? No matter how many books I read on Buddhism, I find no solutions to this question. Please educate me, as I think it is one of the most important questions of many people's lives.