First of all, thank you for your service. I think it is reprehensible that your wife would do this to you while you were away (forbid you to enter YOUR OWN HOME????).
In my opinion, your wife is having an affair. Like someone else said, with the PI you'll find out soon enough. Good for you in having the 'nad to hire one; most people just stick their head in the sand.
You need to get some legal advice, to understand what your options, rights and responsibilities are. Do NOT leave your own home, whatever you do -- that's just about the biggest no-no around here.
I would suggest reading two books: "No More Mr. Nice Guy" and "Hold onto Your N.U.T.S.". You sound a lot like me, in that I used to treat my wife like an entitled princess, and that doesn't work. She almost surely doesn't respect you very much right now, and since women tie their feelings of respect very closely with their feelings of love, you can see your dilemna.
