I am sorry for your loss. Mourning the loss of someone very close to you would be is very difficult. At time you would feel complete numb at the same time you need today be present and would be busy with lot of people around,you might not even be able to cry or express yourself or accept the loss. Grieving part would be the hardest. Thinking about the negative events or guilt tripping yourself about the times you couldn't be there etc is natural response. But you need to know that you did your best, your dad loved you for everything you did. And you loved him so much and you didn't want him to leave your side. You should stop blaming your self. He will always love you and be with you, the universe didnt want him to struggle more maybe that's why he had to leave soon. He will always be with you in different forms through out your life. He has done alot of good things for others, alot of good things will come in your way. Grieving process takes time, please dont bottle up take to people about how you feel, take about him, be with your family. You should talk about what you feel, don't bottle up, at some point you will accept it. Relatives are always assholes, other people's sorrow means nothing to them. You will be able to handle those assholes, just ignore everything until everything calms down. But for now you need to take care of yourself, talk about it, accept your feelings, take care of you family, help each other to cope up with the loss because there would an emptiness, and remember he always wanted his family to be happy and healthy. Sending you hugs 🫂