Hi B. - It sounds like he is trying to get out of his responsibility. I am a military wife and work with our military family support and clearly you need help and the military WILL help you. They do not like and will not accept a soldier behaving this way.
Ok, several questions: how long ago did he leave the family? Did he join active duty or reserve or Guards? has he been assigned to a post or is he still at Basic & AIT? Do you have military ID? How close are you to an active duty military base (if you are a few hours it might be worth making an appointment & the trip)? Do you know of other military families in your town?
Today - gather all of your important paperwork including birth & marriage certificates, and other paperwork confirming your identity and relationship to your husband including any court paperwork. Write down a log of dates/events of what has taken place. Then take the mess of papers he sent you including a print off of the e-mail, highlight all incorrect/missing information. Write down any questions that you have including the spousal & child support. You are also entitled to medical coverage, your kids will always be entitled to that even after a divorce is final. You may even qualify for help with your night school. Now BREATHE! Ok, take a few minutes to go to MilitaryOneSource.com website (MOS). On the categories click on "Relationships" then "Divorce/Separation". Here you will find info that should be useful including: mediation, armed forces legal assistance program, how to help kids with divorce, and much more. Take some time to review and learn. This will help you in the long run. You can always call MOS 1-800-342-9647 to talk with someone.
According to your profile you live closer to Everett than Ft Lewis, so with that I suggest that on Monday make a phone call to the Family Assistance Center (FAC) there ###-###-####. The FAC office is tied in with the state National Guard but it is designed to help and support ALL military families regardless of branch of service or location. Talk to the FAC staff and briefly explain the situation. One thing I strongly recommend is that you stay as calm as possible when talking to anyone about this situation - this will give you creditability, another thing is to take detailed notes of who you talked to, as well as what they said. They will want to help you find out if you are in the DEERS system, if not then have them help you get enrolled in the system. This is your lifeline for pay & medical support.The FAC office can help you get communication to his Commander if needed - again it depends on the answers to the questions I asked above.
You may be able to use the military lawyers to help you with this or you may choose to obtain one of your own, if you choose that option make sure the civilian lawyer knows military very well so they can help you get everything that you need for you and your children. You may qualify for a free or low cost lawyer due to your situation, check with your local Legal Aid for that.
Also make sure things like a "Will" are talked about - what will happen if you are hurt or pass away in an accident?? where will the kids go? How will their support continue, etc? By getting it worked out with all the rest will save a headache in the long haul. If you choose to do a Will on your own do it with Quicken WillMaker program, this walks you through each step plus gives you a detailed manual to read for questions and suggestions and is State specific, it is very easy and has lots of other good info. But in your circumstance I suggest that it be done with a military or civilian lawyer that you work with to make sure any court orders are included.
I am sorry that you are dealing with this but in the long run you will be stronger for your kids. Being in this situation of work, school, kids, etc I encourage you to seek out support in your community (church, family, military family support, etc). You will need a break as well as someone to cry on their shoulder, we can do our best via Mamasource but having someone to help hold your hand will be a major benefit. Don't be afraid to accept help, you deserve it not only for yourself but your kids too! Take some time to BREATHE but it is ok to cry and let it out. You will start to heal and you can help your kids do the same. God Bless!
EDIT: B. - I just talked to my husband about this (he has been in 17+ years) and he said No the Military will not stand for a soldier to do this to his family. I just reread your posting & noticed that you have had communication with the commander. Take copies of all the e-mail communication you have had regarding this when you talk with the FAC office. You may be put in touch with the Family Programs office at his base location or even at the state level. It is possible the commander that you e-mailed with is not following procedure himself so that is where you can take it up the next step. But start with the FAC office, confirm your DEERS status (including address) and hopefully the above info will help you with the rest. God Bless