Hello Kal
I'm sorry you have finally lost your father; 9 years is a long, long time to be dealing with vascular dementia, at least you know that he is now free of confusion and distress.
When my Mum died in 2008, my initial feeling was a great flood of relief that her suffering with this awful illness was over, mixed with anger at the unfairness of it all.
Then a period of numbness, before I actually started missing her (the real her). As you will probably find, grieving is a whole mixture of emotions, some of them conflicting.
Don't fight any of it, you need to go through it.
Kind regards