As others have said, there's no such thing as right and wrong when it comes to grief, everyone and every circumstance is completely individual. I think you can get too caught up in your own and others expectations around what you 'expect' to feel and how you 'ought' to behave at various times and end up just confused or overwhelmed. The idea that there are defined 'stages' of grief you inevitably pass through in a neat order is helpful for some I'm sure but is only ever a generalisation, you can't really compartmentalise and categorise emotions in that way.
I lost my DDad last year quite suddenly and like you and others, have never really been prostrate with grief in the expected way. In the immediate aftermath there was the shock, and then comes the 'arrangements' and need to support others. I recognise that feeling of almost actively trying to work myself up to 'properly' grieve when I finally had the time to do so, but unhelpfully my emotions weren't running to schedule
. I only get really weepy and overtly emotional at inconvenient times and usually set off by feeling stressed or irritated at something else (and once, embarrassingly, at a major family event with my DH's extended family which had very little to do with me, I was desperately trying not to make a 'scene' which of course only made things worse
).
I'm sure isn't this isn't the 'proper' way to deal with things and I do sometimes worry it means I'm not 'normal', but you have to deal with things in your own way and the crucial thing to remember is that none of this reflects in any way on the relationship you had with your Dad or your love for him. I don't know what you believe about people 'looking down on us' after death but I am 100% that when he was with you he knew you adored him, and that if he is still aware in any guise, that you miss him terribly now he's gone.
Would it help you to privately find some way to honour him and your relationship- choosing a nice picture to frame or item to remember him by perhaps? Or just spending some time looking at photos and listening to music, maybe reminiscing with family about happy memories, lighting a candle? Don't expect this to necessarily 'set off' overt emotion if you aren't that sort of person (I'm clearly not) but a way of assuring yourself you aren't just cold and uncaring? 