I don’t blame you. Briefly, sanctifying grace is the grace given to us at baptism which enables us to share in the life of God. To be in sanctifying grace is to be in a certain state. It can be lost through serious sin and regained by confession. If you die in a state of sanctifying grace, you will go to heaven. If you die without it, you will go to hell.
Actual grace is a supernatural help from God and you don’t need to be in a state of sanctifying grace to receive it. It is called “actual” grace because it “actuates” us, in the sense that it motivates us or causes us to do something. Actual grace is given to the atheist that he may believe in God, the sinner that he may repent, the Christian so that he may do good, the martyr so that he may die a holy death.
Basically, if sanctifying grace is a state in which only the baptized Christian may participate, actual grace is a help from God in which any person, baptized or not, may receive. The ultimate purpose of actual grace is to get a person into the state of sanctifying grace and keep them there.
I apologize in advance if the above explanation is not sufficiently clear.