Oh...wow. Have you spoken to a counsellor or anyone as part of defence that can help. we are in Australia so our defence program is different , but we have a community organisation that my DH and I have approached for a number of things (especially dealing with my miscarriage)
Feel free to PM me if you need any help.
Its such a hard lifestyle with both of you in defence. I am actually leaving defence to try and calm any uneasiness.
I do agree with what some of the others have said re: letting her know how much you love her without smothering her. However with both of you being in defence I am sure you can understand how different we all become after a deployment and adjusting back into normal life may make our relationships a little more strained then others.
Have you spoken to her as to why she may be falling out of love with you??

Sorry if that is a bit hard to hear