Grandpa doesn't recognize his own bed anymore. I also help take care of my sister who has autism everyday its always chaos when my sister has a meltdown I try to calm her down but grandpa gets mad when I'm busy with her. And she gets mad when I can't be with her. This is slowly killing me. I'll be seeing a therapist about it.
As for your Grandfather, if you are the only Caregiver, it might be time to place him in a continuing care facility if his memory is that that he cannot recognize his own bed anymore. If money is an issue, see if he can qualify for Medicaid which will pay for his care at a facility. You need to keep his best interest at heart even if it means that he lives somewhere else... you can still "care" for him, but not be hands-on.