I’m very sorry for your loss and offer you my sympathy and prayers. I hope readers will also pray for you that you find comfort and healing.
The Church teaches that we may hope that babies who died unbaptized are with God. The Catechism of the Catholic Church states:
As regards children who have died without baptism, the Church can only entrust them to the mercy of God, as she does in her funeral rites for them. Indeed, the great mercy of God who desires that all men should be saved, and Jesus’ tenderness toward children which caused him to say: “Let the children come to me, do not hinder them,” allow us to hope that there is a way of salvation for children who have died without baptism. All the more urgent is the Church’s call not to prevent little children coming to Christ through the gift of holy baptism (CCC 1261).
You can help your child by praying for his or her salvation and by offering up sufferings for that intention. If your child is already with God and not in need of your prayers and sufferings, God can apply those to another soul in need, perhaps to a child in danger of abortion or to a mother contemplating it that she may receive the grace of conversion.
If you have confessed the abortion and been absolved for this sin, you are forgiven. Try to remember that what you are experiencing now is temptation to despair and will to reject such temptation.
I very much recommend that you seek assistance from counselors trained to help women and men recover from the trauma of abortion. Many Catholic dioceses offer post-abortion recovery through the Project Rachel program. You can call your local diocese and ask for the contact information for Project Rachel in your area. Another helpful resource for post-abortion recovery programs is Rachel’s Vineyard. God bless.