Do I need a lawyer to go to a contempt case? My ex is in contempt for contacting me and not exchanging taxes as agreed and signed by judge. I have court soon and I am not sure if I should go alone. He will have representation. Is this a complicated thing to do?

It can be and without representation you might not get anywhere.
Get a lawyer.

If you go up against an attorney without your own legal representation then the odds are that you will lose. Even if you are in the right.

You should expect to lose if you do not have an attorney and they do. An attorney would use words you don't understand, file a motion perhaps you don't know how to address and more

Who presented the contempt to the Court? You? What sort of dollar figure is the not exchanging taxes? If the Judge so ordered this and you can't afford representation the Judge should rule in your favor. After all, it was the Judge's Order that your ex defied. I'm not too sure that anything regarding the contacting you business will get your ex any jail time but your ex will have to explain to the Judge just why no tax info was not exchanged.