Look for the contributions by Nords. He was in the military and ER'ed successfully and his contributions are great to read.
Then, tackle your habit of spending money in ways that do not support your goals in life.
This does not mean that you should not buy things for your family. But you could be more creative to find alternatives to buying as your sign of love.
Long term, no kid misses the toy that Daddy did not buy. But they all miss the game that Dad did not play with them, the book that Dad did not read to them.
If you feel the urge to buy as sign of love, put the item on a list for at least a week, go home instead and try to express your love in a special way that does not involve consumption.
It is highly recommended to start keeping track of expenses in writing and as detailed as possible. Create budget categories and monitor at least monthly. Only if you know exactly where your money goes you can find opportunities to save, attack useless expenses and see your progress. There are lots of contributions here on tracking expenses.
As you wrote, your family has some obstacles with only one income. But look out for examples of other one income families like on www.slnet.com's
forums, or on The Dollar Stretcher: Frugal Living since 1996
. Get a copy of the "Complete Tightwad Gazette" and of "Your Money, Your Life" from the library or buy used. Lots of ideas and examples, even though the prices in the examples are outdated by inflation.
Share your dreams and goals with DW. You need to work as a team and her support will help you in your daily work and she might come up with some ideas as well.
All the best to you and to your family. Please keep us updated.