Can it be variance if you constantly lose? How do you find the holes?

[sfetaz]

I recently decided to be serious with limit online poker. Deposited $600 into full tilt to play 1/2 limit, started posting on 2+2, reading more books and getting myself serious into limit. I track my stats and others, I am tight aggressive and find my stats mostly where they should be. Yet somehow most of my sessions are losing sessions. It's very frustrating and I don't know where to look to find holes in my game. Nearly everything I read in poker tracker looks correct to me. It even rates me as tight aggressive. I know stats alone don't dictate a good player but I feel like I do things correctly more often than not. It's not simply bad beats that I am losing money on. How does someone figure out what they are doing wrong or if it actually is variance?