I hope that my words will come across as kindly as I mean them, but they may sound harsh just because they may be other than what you want to hear. Let me also add that I am Annie, a stay-at-home homeschooling mother, despite my user name.
Life is full of decisions and also full of problems. I used to look at situations other than my own and think that they looked better than the situation I was in. That is a very human reaction, because we see all the warts of our own situation, and only the good outside of other situations.
You have made decisions. Some were good, but some… not so good. You decided to have sex when you were not married, not ready to have a baby. (You then went on to make good decisions, to have your baby, etc.,; I am not commenting on the morality of your decision but the fact that you did make a decision.
And see, your decision was not compatible with what you wree doing at the time, but by making the decision, you were in effect deciding against definitely continuing what you were doing at the time, since your decision was one that included the potential of a baby.
That decision was also potentially (and turned out to be) one of becoming a mother. Luckily your then-boyfriend accepted *his *responsibility in the matter too (not that it would have been necessary for him to marry you to accept his responsibility, but he did both, accepting his responsibility and marrying you). So your life is much easier than it would have been had he not done either or only one.
Now, our society says that a person is valuable because of the *economic *contribution they make to society. Women who stay are home and raise children are *not *considered valuable.
Moreover, most sex-ed classes emphasize not getting caught to the point that I believe even married women feel somewhat flustered about having children, esp if they then stay home with their children.
There is a disconnect between ourselves (sah mothers) and society. This can be incredibly tough!!! We spend years in a world where sex is ok and being pregnant or having a baby is not ok; a world in which working for money is what gives us value, and staying at home is sneered at. In short, we SAH mothers are running very much against what society has told us all our lives.
(Just as an aside, I would like to say that I believe that each family should arrange itself in the way that *best *suits all its members, and that may involve a mother working outside the home for whatever reason other than social pressure

as long as this works out for *all *the members of the family, so I do not in any way mean to imply that there is anything wrong with mothers having jobs outside the home.)
You, my dear, are at home with two small children. You fear the addition of future children. I think that you need to think about why precisely you feel that way. And this would be best undertaken with someone you know in real life or can meet with in real life–ideally some woman who has learned to find happiness in her family life and considered these issues, but some friend or counselor (priest, NFP teacher, psychologist) who would be able to help you sort this all out.
Being a military wife can be very difficult. I grew up in a military family, and my husband, altho not in the military, has had to be away from home for his work a lot. There is the constant knowledge that things can change at any minute, making it difficult to really settle into any community; there is the constant coming and going of the husband/father–and this is a real transition: the family must function when he is gone, but open up enough to let him back in when he returns and this can take weeks or months of readjustment.
I hope that you will look for and find someone with whom to discuss these issue irl, because it is easy to see that you are feeling a lot of pain over them. It is hard, when one is feeling pain, to be the best one can be.