I noticed you said she was expecting? There could be medical reasons why she's defensive and seems moody. I know for a fact that when I was carrying my 2nd child, everything was intensified almost like I was PMS'ing the entire pregnancy! He even said at one time "All pregnant women should go to some island till it was over.. "
I agree though no matter what the reasons behind her insults and fights that you both should seek a 3rd person to see both sides of the story and maybe he/she will be able to help you and her work through this. If she is young, thats another thing, maybe she has some hidden fears of being tied down with responsibility of the baby and taking that frustration out on you. People do strange things when they don't want to deal with reality.
I'd wait till after those hormones are not messing with her and even a few months after the pregnancy to do anything hasty. She might return to the person you fell in love with and married, it just takes time and patience to find out especially if you really love her... There's not a perfect marriage out there, so expect some ups and downs... through sickness and in health etc.. I hope you the best and pray for you both and a healthy delivery!
There are two days in the week about which and upon which I never worry. Two carefree days, kept sacredly free from fear and apprehension. One of these days is Yesterday... And the other day I do not worry about is Tommorrow.
~Robert Jones Burdette