My father freaks out when they try to bathe and dress him?

My dad is 82 and is currently living in a memory care facility. He moved into this facility about 6 months ago following a very abrupt departure from LTC. My father has dementia, but for the past four years had been pretty independent (transferring in and out of bed, toileting and eating independently). He did require some assistance with bathing and dressing, but that was it. SOMETHING BAD happened in his previous facility which resulted in an ER visit, hospital stay, and never going back to a place he called home. Upon his discharge from the hospital (and I to the new facility), a dosing error was made with the medication, DEPAKOTE. He was accidentally prescribed a dose that was three times the normal amount he was supposed to take. This mistake turned him into a lump of lifelessness. Dad could no longer transfer out of bed alone, stand, or eat alone, and definitely could not wash, dress, or toilet independently. While he remained a lump of lifelessness, nothing bothered him (he was barely existing) and no one at the new facility, thought anything of it (considering they did not know who he was 3 weeks prior). Since then, although it has been a long road, I have managed to prove to the new facility that the DEPAKOTE dosage was a mistake, and now he is off of it entirely. THE PROBLEM that has arisen as he has become more aware (and less lifeless) is that he completely panics during washing, changing and dressing. He Absolutely freaks out and has even gotten combative with the staff. But once the task is finished, he’s completely calm and content for the rest of the day. My father does not exhibit this behavior at all during the day, JUST during changing and dressing. The new facility, which I do love, has suggested we medicate dad with Ativan, Xanax, or some other medication that will allow them to do wash and dress without such a fight. The problem is, regardless of how comatose, my father may get from these meds (and he will become comatose because I have seen it ) he is quickly wakes up and throws himself into fight or flight mode during changing dressing or bathing. I have become very anti-medicine, considering I could’ve lost my father from a mistake that was made by a neurologist in a hospital. I don’t want him to be a zombie or at risk for an earlier death, but I also don’t want him to feel the stress every morning and night, like he has to defend himself - when he’s just getting washed or dressed. I have spent countless hours researching suggested techniques for the facility to try to keep him calm and reassured during this task, but they tell me it’s not working. How can I possibly be OK with chemically restraining my dad, when this behavior is so isolated, and I believe in my heart that he is suffering from some sort of PTSD from the other facility? I suggested that my father be visited by a therapist, in hopes that she may be able to uncover something that happened, or just be able to reassure him that he’s safe “now”. I don’t know what else to do? I feel like we’ve tried everything. Help Please!