Perfect contrition is not necessary for your confession to be valid. If you had sincere imperfect contrition, such as fear of the loss of hell, along with a sincere acknowledgment that you have sinned, that is sufficient for the sacrament to be valid.
I think you are in the same position, in some ways, as people who had a child out of wedlock with someone they love. You can’t deny the good that has resulted from your actions, and therefore, it is difficult to see that your actions were wrong.
Remember, though, that in His abundant goodness, God often draws good from our sins. But that doesn’t mean they weren’t sins. It also doesn’t mean that it was His will for you to do what you did. Rather, because he is so merciful and knows the sincere motives of your heart, He will often draw something beautiful, like an innocent child, from acts that are objectively evil.
It is not for anyone on this forum to say you’ve sinned. This is between you and God. All we can do is discuss the objective morality of an action, such as IVF. The subjective guilt is only for God to judge.
So my advice is to thank God for the wonderful child He has chosen to bless you (and the rest of the world) with. Give Him glory for His generosity and goodness. Realize that He is really the one who created your child and sustains him. Rely on Him for the help you will need over the years to fulfill the mission He has given you.
And at the same time be willing to go wherever the truth leads you. By entrusting this child to you God has already shown you that He will not condemn you for your actions if you seek Him and His Truth with a sincere heart.
Don’t fear that the possibility of acknowledging that you may have done something wrong in using IVF means you must feel guilty about having your child. You don’t. Your child is a true blessing from the Lord. Your job is now to raise him in the fullness of the Truth. And to do that you must come to accept the fullness of the Truth yourself, whatever it may be.
The Truth will set you free. Seeking the truth about our actions allows us to acknowledge all our sins, but in a way that leads us to love God all the more and praise Him for the bountiful love He showers upon us, despite all our sins.