What are the procedures on getting an annulment under six months?

There is no set time frame for obtaining an annulment. N.J.S.A. 2A:34-1 provides the following grounds for annulment: a. Either of the parties has another wife or husband living at the time of a second or other marriage; b. The parties are within the degrees prohibited by law. If any such marriage shall not have been annulled during the lifetime of the parties the validity thereof shall not be inquired into after the death of either party. c. The parties, or either of them, were at the time of marriage physically and incurably impotent, provided the party making the application shall have been ignorant of such impotency or incapability at the time of the marriage, and has not subsequently ratified the marriage. d. The parties, or either of them, lacked capacity to marry due to want of understanding because of mental condition, or the influence of intoxicants, drugs, or similar agents; or where there was a lack of mutual assent to the marital relationship; duress; or fraud as to the essentials of marriage; and has not subsequently ratified the marriage. e. The demand for such a judgment is by the wife or husband who was under the age of 18 years at the time of the marriage, unless such marriage be confirmed by her or him after arriving at such age. f. Allowable under the general equity jurisdiction of the Superior Court. Annulments, however, are difficult to obtain and are rare. It is established only when there is proof of extreme nature going to one of the essentials of marriage. A textbook example is when one of the parties to the marriage subsequently discloses intention never to have children after there is an implied promise to have children. Another example is when it is later discovered that one of the parties entered into the marriage solely for the purpose of securing permanent residence in the country. You should file a complaint for annulment and seek divorce as an alternative form of relief.

That is not the basis for an annulment; you have to file for divorce.

Cheating is not a ground for annulment (in Colorado it is called a declaration of invalidity because "cheating" during the marriage has nothing to do with whether the marriage was not legally valid at the time of the marriage.