Does a contract that both parties signed and agree to hold up in the state of Indiana if it’s not notarized

There is a lot more informaiton needed to respond in detail to this question, but it sounds like you consented to a guardianship of your child/children.  If you no longer agree to the guardianship, you can request the guardianship be terminated by making a request to the Court in which the guardianship was filed in.  If there was a previous paternity or dissolution case, there may be other options as well.  In any case, you need to obtain any existing Guardianship Order to determine who has legal custody and if you have parenting time or have been ordered to pay child support.