How can I help my dementia Dad sleep at night?

Not sure if it makes any difference my dad can't sleep at night and that means he gets up allot at night because he wants to use bath room, gets very confused in day & has sundowning. Talked to geriatric doc, deralogist & sleep doc. We seem to spinning our wheels with not much help from them. His temper was not good but we give him natural calm that seems to help a little. He is in a bunch of meds including depression pill. I wish I could be with him all the time seems like I'm the only one that gets threw to him but once I leave he reverts back to losing his mind. Ive made a dvd to talk to him when I'm not around, have family videos, pictures, caregivers 24-7, write notes I try to do everything for him and promised him I will not give up. Does anyone have any recommendations to help?