Moving away from my family

My fiance is originally from Pittsburgh, PA and moved out here to NJ to be with me almost 3 years ago. He was raised by his grandparents and they both turned 80 this past year and their health is definitly declining. We are talking about moving back out where he is from within the next year for the next couple years to help care for them and just all around be closer. I am fine doing that for him, I love him and he's my best friend and I don't want him to regret not being near them and their time is dwindling down but does it also make me a horrible person wishing we didn't have to possibly do this? I am extremely close with my parents and my sister is hands down my best friend. Has anyone else ever had to move away from their family ? How hard was it? what helped you get through the transition