Am i entitled to any benefits automatically if my husband joins air force and we are separated (not legally)?

My husband and I have been separated for almost 9 months, he left me for another woman, me and my son had no where to go, he hasn't paid child support and he hasn't done a thing for us financially or otherwise. Now he is taking steps to join the military, he took the ASVAB and scored well enough to go into the air force. All he has to do is get his tattoo removed from his neck and he has already completed one session so I'm uming he will be going in the next few months. We have signed a joint petition to divorce, notarized it, but I have not turned it in and don't plan to now that I found out he will be in the military because I know there are many benefits (financially, health insurance, school financial aid - i am going to start nursing school in august) to being a military spouse. If I can hold onto the marriage on paper until he is officially in the Air Force, will I automatically be entitled to all these benefits or will he have to disclose that he is married and give them my information and all of that before I can have any benefits. My problem is that I know he will cover my son on insurance but I know if he has the option not to, he will not want me on any benefits (he is vindictive like that). So when he joins, if we are still legally married, will they need to know that or is it possible he can just say he is single, etc, etc. We filed our taxes together this year, we have absolutely nothing stating we are even separated let alone divorced and our separation is not legal. Please give me any and all info! Thanks!