How do you deal with personality changes after tach stroke

[Ariadne43]

My father had a very dense tach stroke approximately 6 months ago.  Our active 80 year old father who was happy go lucky has turned into a completely different person.  He is severely disabled now and his denial is getting worse, he thinks that we are keeping him from walking despite the fact that his left side is completely paralysed.  He spends his waking day complaining and bad mouthing the family who have gone out of their way to help him.  My brothers have spent nights with him and yet he still gives them abuse.  He is so aggressive now and self absorbed and he is fixated on unimportant things.  I just hate to be around him, does anyone else feel like this?  We got the doctor out to see him and the doctor told him that we need to spend more time with him.  Any words of advice anyone?