You don’t have to wait until his memorial service to tell your father the positive things he means/meant to you. Don’t misread his emotional shyness/embarrassment/awkwardness as his not wanting to hear it. His awkwardness is often due to his starving to hear it and that ache overwhelming him. BTW if he has died, you can still do it by visiting his gravesite or even to a picture of him.
Love you dad, miss you dad, rest in peace.
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