Welcome to the forum and thanks for sharing your story.
If you click on the link at the top of the page you will be able to access many articles on the aging narcissist if you haven't already done so. Knowledge is power with this illness, and as a child of a potential narcissist, you will carry a swag of behaviors which are not helpful to you and also carry false beliefs about yourself which were planted in childhood and against which you had no "normal" template to measure them against.
Now, you've had your "wake up call" because you have decided to do something for yourself and, at the age your father is, this is definitely not allowed! Hence you will likely be finding yourself under a lot of pressure to conform, and if you do not do so, further pressure will be applied, you may be scapegoated, gaslighted as you say, and a host of other techniques to get you to toe the line. This can be very difficult to deal with, and the first thing you need is knowledge and to learn how to set boundaries. You may also have guilt to deal with when you attempt to have a life of your own and not make Dad No:1.
If you need assistance, I would suggest booking a session to determine whether NPD (or other co-morbidities) are present, and if so, you will then have a platform to start changing your life into one where you feel in control, despite the behaviors of your birth family to get you to conform to the family pattern. This can be done! It takes time but it's worth it for the freedom just to say "No".
You can book a session at http://youronlinecounselor.com/Services.htm
or alternatively contact me at email@example.com
for further information.