Are there any other children of absentee fathers here who are really insecure about their ability to be a dad?

My twins are 2.5, and I always just feel like I'm winging it because I have no frame of reference. My dad was an abusive alcoholic who dipped either right before or after I was born. He never so much as tried to contact me. It's clearly a good thing that happened because of who he is, but it makes me feel like I'm way behind the 8-ball on being dad to my twins.

I also feel a lot of guilt for not being able to provide them a second grandpa; I was always envious of classmates who talked about having two sets of grandparents.

Lastly, I just always worry I'm going to, I guess, become him. Like if I get reflexively angry at them and have to consciously stop myself from yelling at a literal two year old or feel like I don't want to be around them when they are doing normal toddler chaos--I get this extra layer of guilt and fear that I'm just destined to be a shitperson to my kids because my dad was a shitperson to me.

I don't know. I know that last part isn't rational. I was just wondering if I'm alone here or if there are others in this boat with me.