What have you actually done and how much is the total you have defrauded? Under certain circumstances if you admit it and offer to pay back, you will get an administrative penalty (ie, no criminal record). However, if it is more than about �2k and the claim was fraudulent from the start, yes you are likely to end up with a criminal record.
In the past, lawyers were not obliged to notify the authorities of criminal activity but under the Money Laundering Regulations, they are obliged now to inform NCIS.
Is your husband in any complicit in this fraud? If so, he could well be jointly charged so it may be as well for him to cooperate with you.