Does one understand dementia?????

How can one assume that they know dementia very well when they don’t even know the stages of dementia and how it actually progresses.  My dad has dementia and what my sister had recently done could have indirectly cause some problem.  She tried to clean up the place and in the end these few days my dad has become more confused and better part is he becomes more withdrawn.  My mom told me he is very attach to me cause maybe its also because i tend to spoil him.  He is in the 4th stage of Alzheimers and has lewy dementia, so yup the way of handling him is almost the same as handling a toddler.  Most people do not understand like my sisters.  Should I titrate his Olazapine medication is another question that I ask myself everyday.  The doctors did tell me to try and wean down and I did to 1/2 a tablet instead of 1.   This is a anti-psychotic type of drug that increases confusion.  What should I do and why?  I need more time to spend with him directly so hoping that in a way this might slow down his deteoriation of the dementia.  Although dementia is not an illness but it can disrupt a family life is mishandled.  Most likely I will be going for a week holiday and so I have to prep a lot of stuff for him like the essential oil diffuser and also his medication for that period of time.  I have no idea with so many things going through my mind each day.  I wish to pursue my own interest but at the same time have to think a lot, tough but somehow I will get through this.  No matter what I will have my own ideas and method to handle.  I haven’t had a chance to see my grandma till to date since she was hospitalised. I hope can at least see her tomorrow morning