if gal doesnt listen to both sides and believe that lies of the mother

This is a frequent complaint of litigants involved in custody litigation; the parties cannot agree to a placement schedule and the court appoints a guardian ad litem to advocate for the child's best interests; in some counties, the court may also appoint a social worker to assist in the investigation; inevitably one of the litigants gets the vibe that the GAL or case worker is one sided or appears to be against then in their recommendations to the court. Remember however, that the GAL is an attorney and cannot testify at the court trial; the GAL makes recommendations which the trial court can accept, deny or modify in a way that they deem is best; ask around from people you know or talk to an experienced divorce lawyer in your county on what they know about the GAL and more importantly  what they know about the particular judge on your case; is the judge one who may just rubber stamp the GAL's recommendation, or are they more of free thinker and may do their own thing? If you feel the case is going badly for you, you might decide to strike the best deal you can right now with the other parent and not risk losing anything more at trial. I know it's a tough decision either way.