i feel for you, my wife is 11 yrs older than me, and my oldest is only eight yrs younger lol.
I had a great dad, but everything got thrust on me so fast that i dont know how to parent well. That's one of my wife and Is biggest issues, because I tend to be too firm and sometimes harsh. I try my best, but sometimes its hard tk be patient, eslecially with the oldest.
Theystill dont call me dad, nor do I ever suspect they will. The oldest will on occasion, but it's generally when she wants something lol.
You will llearn, it all comes with time.