How could I recover from the death of my father whom I didn't get the chance to know better?

I grew up in a turbulent environment and my parents separated and got back together for so many times. The very last time my dad came back, was 4 years ago and he was stricken with a debilitating stroke. (My Mom was already living in abroad for 9 years out of frustraton.) That was the last 4 years that I spent with him but I felt that it was not enough. There's this unsettling feeling along with feelings of confusion. My sister and I took care of him but it came to a point that we grew tired, but we still did what we could even if we had to drag ourselves to do it. When he finally died last Aug 27, I still have a lot of confusing feelings and what ifs. The last thing I did the night before he died was hold his hand, but I didn't get the chance to hug him or tell him that I loved him despite all the wasted years that he wasn't there. I just didn't know HOW to love him. I felt that I took care of him out of obligation. Kindly answer this question with sincerity, I don't need BS ones.