Not disclosing your arrest is a risky move because your probation officer is probably going to check for arrests before processing your discharge. As a former PO myself, I always respected the honest folks I dealt with. However, if no action is taken on the violation before the expiration of your probation term, your PO can't re-open your case to pursue a violation. If that occurs, you can bet that the DA will use that against you in any plea negotiations. DUI is a class A Misdemeanor as is...
This is a very serious charge. It is impossible to tell you on this forum what sort of plea bargain could be offered. I strongly suggest that you contact an attorney right away. I would also refrain from make any more specific references as to what you did or did not do.
DUI 1st is a Class A misdemeanor punishable by up to 11 months 29 days in jail. It requires a minimum sentence of 48 hours in jail with the remainder of the time on probation. There is really no way to tell you what to expect without a thorough review of the facts. The cops say you failed the tests but did you really? What was the reason for the stop in the first place? These are things you need to speak in depth with an attorney about. Feel free to contact my office if you want to discuss.
Unfortunately, these things happen and it appears to be due to a lack of communication. The first thing your husband needs to do is to call his lawyer and find out the status of their relationship. It seems odd that he has not heard from him in 2 months. His attorney may be able to arrange for the warrant to be set aside. If this truly is a situation where lack of communication caused the missed court date, there is a good chance he will be able have the FTA charge dismissed.