Try to be objective. You might discover a better way to approach your job or simply a new way to peel a carrot. You might also learn that there is no better way to care for your loved one other than just the way you have been, which is a valuable lesson in itself. Don't be afraid to watch and listen. Don't be afraid to let go for a while.
Caregivers have needs, too.
Don't feel selfish in seeing that your needs are met. Just be sure your relief caregiver is prepared. After caring for my stepfather, Ed, for several months without a break, his son, Greg, arrived from Virginia to take over. I was immensely grateful and eagerly met him at the airport in Portland. On the drive back to the house I realized he hadn't a clue of what he'd stepped into.