Know that your feelings—even the highly negative ones—are widely shared by others who have also gone through the experience of caring for a loved one who suddenly faces new or worsening cognitive impairment, disease, or disability. Your emotions are your emotions, but what you feel does not have to define your future or how you act.
What matters is how you manage those emotions. You may feel frustrated that your aging family member is acting belligerently, but you still meet her where she is and treat her kindly. You may wish you didn’t have to be a caregiver, but you still perform your duties to the best of your abilities. You may miss how things used to be, but you don’t let that stop you from living in the present and planning for the future.
Accepting that you are likely going to experience grief when you assume caregiving duties means you are more likely to recognize grief reactions when they strike—which means you know what you are dealing with, so you can seek out the help that you need in that moment.