If I’m getting divorced and am not staying atour house, can I stop paying my half of the mortgage?

As a general rule, financial obligations that were being paid before separation should continue to be paid (e.g. mortgage, car loans, health insurance) until a court order is issued (e.g. final divorce decree) or a legal separation agreemnt is entered into.   Additionally, your failure to pay could possibly play a factor in the distribution of assets. 

You need to be aware that your marital condition has nothing whatsoever to do with your mortgage obligations per se since your lender doesn't care if you're single, married, divorced, separated, annulled, etc. The total amount due under the mortgage must be paid; if it's not, the bank can foreclose and take the house, then potentially sue for any additional balance due.

Speak with a family or divorce attorney before doing anything. First, it will probably look bad to the judge, and could also affect distribution of assets (e.g. because you stopped paying what you should, that will likely, in one fashion or another, be taken account of in support and/or asset distribution). Second, if you stop paying, your wife could, even outside of the divorce proceeding, sue you for your contribution; if she can't or won't pay the full amount herself, the mortgage will be defaulted on, which could result in foreclosure (losing the house), being sued by the bank, and/or a serious negative impact to your credit rating. Your desire to not pay is natural; but there are serious ramifications you need to discuss in detail with an attorney first. Good luck.