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.
First of all, you should take the initiative to repent for having committed Zina (fornication or adultery) with that man, and also for having committed abortion, becasue abortion is forbidden at the different stages of development of the fetus according to the most preponderant opinion of the scholars; the sin is even greater after the soul is breathed into the fetus. For more benefit, please refer to Fataawa 85930 and 83891.
You should know that Allaah accepts sincere repentance of all sins, even disbelief and Shirk [associating partners to Allaah]; sincere repentance wipes out all previous sins.
As for abortion, if it took place after the fetus had taken human form (i.e. 40 days or more), then it is an obligation to pay the Diyah (blood money) for it as we previously clarified in Fataawa 98739 and 133269, and we mentioned in them its amount in gold and that it is converted after that into its value in currency [cash money]. Therefore, its amount varies according to the price of gold.
Since the mother of this fetus is a Muslim, the Diyah should be given to the Muslim heirs of the fetus, but whoever carried out the abortion has no share in it as we clarified in Fatwa 134360. And if the fetus has no Muslim heirs, the Diyah should be spent on the general welfare of the Muslims.
It should be noted that the rights of human beings, among which is the Diyah, are not dropped by one's being unable to pay it; rather, it remains a debt on him/her until he/she pays it.
Concerning the obligation of the expiation for killing (i.e. fasting two consecutive months), there is a difference of opinion among the jurists in this regard, but it is better to expiate in order to be on the safe side. For more benefit, refer to Fatwa 128722.
Allaah Knows best.