Yes, it can be done. You do not need to be living separately. There are a lot of things to talk about before you try to do this. A smart lawyer can help a lot.

Yes, you can file for divorce while still residing in the same household – because of constrained finances, many people, in fact, do just that. You do not need to be living separate and apart to file for a divorce. New Jersey allows for divorces based on irreconcilable differences. All you have to plead in your complaint for divorce is that you have experienced irreconcilable differences leadings to the breakdown of your marriage for a period of 6 months or longer, and there is no reasonable prospect of reconciliation.
Divorces can be highly complicated, even, or perhaps especially, when there are limited financial resources to go around. It is important that you discuss the specifics of your case with an experienced matrimonial attorney to learn more about the divorce process, what your rights are, how to protect your interests in family court and what to expect as you go through the process.

Additionally, below are links to articles and information that may assist you with your case.

There is no requirement that you reside in separate residences. Under Irreconcilable Differences, all that is required is that you have not been able to get along for a period of six months. What was likely being referred to was the prior "no fault" case of action that required 18 months of separation. While that cause of action still exists, it has been largely replaced by the simpler irreconcilable differences which requires a much less to qualify for a divorce.

It's rare to see a group of lawyers answer a question with such unanimity, but yes -- you can obtain a divorce in New Jersey while still living together. It was once required that, in order to obtain a no fault divorce, you needed to live apart for 18 months. That changed in 2006 with the enactment of "irreconcilable differences" (and was always available if fault grounds were used). I have had matters where the parties got along and decided to continue living together (sometimes in different areas of the house) long after a JOD was entered.

Under the facts you describe you may file for divorce, although living in the same house. the individuals I have represented have lived in separate parts of the house or separate bedrooms.

No as other attorneys have pointed out, 6 months of irreconcilable differences. Think long and hard about sharing the house afterwards, though. It may create even more problems as with no income there may be use/misuse of each other's assets or other issues. Nothing to stop either from bringing home a "date", for example. Really messy possibilities.

No need to live separately to file for divorce. Not only do many couples live together while the divorce is proceeding, but some continue to reside together after the divorce until their home can be sold.

There is no requirement that you be living separately as a condition to proceeding with a divorce action. In fact it is not uncommon for parties to reside together during the divorce process.

Absolutely not true. You can file for divorce under the no fault cause of action Irreconcilable Differences if there has been a breakdown of the marriage for a period of 6 months or longer and there is no possibility of reconciling. This means that although you reside under one roof for purely financial reasons, you are not living as "man and wife" meaning, for example, you sleep separately. An experienced family law attorney will draft a complaint for divorce on your behalf and indicate the reason you have the same address in the complaint. You should take advantage of the free consultations many family law attorneys offer.

That is not true. You can file for divorce based on irreconcilable differences for at least six months and still reside in the same residence. I suggest you consult an attorney.