Has 15 mos. been too much?

As some of you know, I have been a "workout warrior" since my banding in late Aug 2007. I haven't had many problems with my workouts. I've lost 135 lbs in that time period and cut my bf% from almost 34% to 17.5%.

I circuit train mainly for my workouts. 3 circuits each workout, split upper body and legs and do each 2/wk. I start with 7 reps and increase by 1 rep each week until I get to 12 reps, a 6 wk cycle. Then, week off and start all over with increased weights and different exercises for each body part. Also, I do at least 50 minutes of cardio on days that I work and 65-95 minutes of cardio on days off. Lately, I've been giving myself 1 day off from exercise completely each week.

Now, this 6 wk cycle has been different. I feel "weak" in the middle of my 2nd cycle. I'm at the tail end of this cycle and I failed on the bench during the 2nd cycle of 12 reps. As soon as I hit rep 7, I knew I was not going to see rep 12 w/o stopping. That has never happened before.

My question is this: Has 15 mos straight of doing this been too much? Even though I have been taking a week off btwn cycles, have I overdone it? Am I reading too much into what happened? Is the fact that I am not taking Protein supplements during the day killing my workouts?

I did stop the Protein shakes during the day to help out our home budget. Do I need to look at cutting something else out to make sure I can purchase the protein?

Any advice would help.