All perfect praise be to Allaah, The Lord of the Worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad is His slave and Messenger.
We congratulate you for your repentance to Allaah from this grave major sin, and we ask Allaah to accept your repentance and enable you to perform more good deeds in the future.
We advise you to befriend righteous women, and if you are not yet married, you should endeavour to find a righteous husband who would help you remain chaste and steadfast on the religion of Allaah. For more benefit, please refer to Fatwa 86703.
If you are pretty sure that the abortion took place after 40 days of pregnancy, then you are obliged to pay the Diyyah on it, and it should be divided among those who would be the heirs of the foetus had it lived. Each heir gets an amount according to the share which is prescribed by Allaah to them. For more benefit in this regard, please refer to Fataawa 85558, 86841 and 98739.
The grandfather [from the mother's side, who is your father] does not inherit because between him and the dead is a female; the rule is that any heir who is related to the dead by a female, does not inherit.
You should know that the fornicator does not have any relation with the foetus, so he or his relatives has nothing to do with the Diyyah of this foetus.
You are not obliged to inform the heirs that this money is a Diyyah; what is important is that each one should be given his exact share.