What am I doing wrong...2 months watching and nothing

Sorry this will be long.... Background: I'm 27 W is 29. Been together 8 yrs/married 4 No kids. Knew each other since grade school but weren't really friends more like acquaintances (different grades and social cliques). After high school ended up going to the same college as her and we bonded and eventually started dating after my first year. Long story short I ended up leaving school the next year, got disowned by my folks, and then lived with her in her apartment her parents paid for. Her parents eventually fell on hard times and couldn't afford her apartment so I ended up working 2 full time jobs and rented us a place so she didn't have to work and focus on school. This continued as she went back to get her MBA. Despite all the hrs and how tired I was I always made time for her and showed my love and support for her and she did the same Right after getting the MBA she got hired cross country for a job that paid 120k a yr. Yr later we were married and she encourage me to go back to school get my degree as well. (I put off going back until last year) Fast Forward to now: Since Dec/Jan she has been acting strange. She isn't mean or cold towards me just sad and withdrawn all the time and not wanting sex. She has to travel a lot more since then for her job and when she home she works later hrs. (I at first didn't think much of this since she recently got promoted). She also began to working out more (despite the fact that she is was already in perfect shape) at night at the 24 gym by our house and having girls night more frequently. I started getting suspicious on Valentines when despite everything I did to romance her that day she was extra sad for some reason she wouldn't even braking down crying at one point and wouldn't tell me why. My friend pointed out she could be cheating so I hit google and found out about the red flags she is throwing up. I eventually found this site and was lurking for a while and learned the do's and don't's in this kind of situation. Mid-April after my b-day (which I didn't even see her most of the day) I went full Jame Bond on her a##. I got 3 vars put one underneath the her driver seat, in the bedroom behind my nightstand next to the bed, and in our den where she spends most of her time in the house. I also installed a gps tracker in her car, key logged her laptop, keeping tabs on the phone bill for frequent unknown numbers and even put up a few spy cameras in the house. 2 months later and still nothing but nothing has changed really. If anything she is even more depressed. I just can't shake the felling something is wrong. What am I missing? (Sorry for the short story)

Put the internet to work for you. via Personal Recipe 2629979