Fathers are particularly vulnerable in our present cultural climate. The problem may be mild to severe. Do not miss deadlines for answering or filing your discovery request - failure to prepare is not reason for the court to adjourn your case and often, admissible evidence is excluded based upon failure to comply with or participate in discovery within prescribed deadlines. Often it is particularly important for fathers to use psychologists in order to establish adequate proof that the children will develop better under his care than the mother's. If your spouse has an expert, then you should have one.
Experts can base their opinion on otherwise inadmissible evidence such as hearsay.
Disclose the name of your expert before the deadline to do so, otherwise, you may not be able to use his or her testimony. Then stress your positives. A settlement cannot be appealed unless you can prove it was obtained through fraud, so be prepared to go ahead with a trial and call your witnesses if you are not happy with their offer. For questions about your own particular case consult an attorney. Good luck in your decision making and my best wishes to you in all your wonderful parenting efforts.