Can I be held in contempt of court if I don't release my child to my ex's girlfriend for visitation and require they he pick up the child?

Maybe.  Not nearly enough information.  What does the order require?  Is there an order?  If the two of you are on the birth certificate as parents, and there is no order, you have joint legal and physical custody under the statutes, and unless there is an order, there is nothing to be "in contempt" of.  Yoiu really should speak with a family law specialist.