If you sit down with your Realtor and/or his/her Broker and explain your situation they might release you from the contract - be sure to get the release in writing with the Broker's signature. The listing really belongs to the Broker and not the Agent.
Best of luck,
This is not legal advice. For legal advice see an attorney.
First, I would think if you discussed with your Realtor they could help you work out an arrangement to take your home off the market.
Second, in most states it takes both husband and wife to sell their home. If you don't want to sell, they I doubt your wife can force you unless she has a court order or something similar.
Whether there is a penalty or cancellation fee would depend on what is in the listing agreement.
In most cases an agreement will be reached - especially since it seems that your home will not be sold at all i.e. one of you will keep the home.... But you must discuss the terms of your listing agreement and then get a written release from the brokerage company and there may be some conditions in that release depending on your brokerage company and depending on the listing agreement itself which you signed with them.
Talk to your Realtor first and go from there!
Sorry about your divorce and I hope all will work out for you in the end.