If your dad was a proper fellow before this happened, then you must always keep in mind that he is not well, and his true spirit means you no harm. So, keeping that in the forefront of your interactions, that he is not well and of not of his right
mind............You need to be strong and firm, and say no to any close contact that makes you uncomfortable. Remember, even when he is not himself, his rights end where your's start. Be consistent, strong, and remember tough love is still good love. As to his behavior w/ other women, give them a head's up as to his condition, and play each of those by ear, including limiting contact.
You can do this. Tough love. You have a right to your own dignity and self-respect.