Mine dropped too when I was sitting for level II. When I got mine tested, b/c I was feeling weak, my results came back below range, 298 ng/dl, and Free T was way low. After the Level II exam I resumed normal sleep, diet and exercise and my T rose back up to over 500 ng/dl, in the mid-normal range, and Free T was in the upper to normal range. I also had varicoceles which I am sure was affecting things, which has since been fixed.
Stress, diet & sleep are huge factors that contribute to your T levels. You produce the majority of your T while you sleep so if you are getting less than 8 hours of sleep then your T will be low. Also, the stress hormone Cortisole interferes with T levels so if you have a lot of stress your T will be low. When I was studying, I was constantly stressed out with studying, work, and family, so I am sure my cortisole was sky high, and I was going to bed each night at 1am and waking up at 6am, which raises cortisole as well.
Try to raise your T naturally by lowering your stress level, get more sleep, have more sex, and get plenty of exercise. Also, check to see if you have a varicocele, because 1/5 guys has them and they affect T production. If you start waking up with morning wood again and your sex drive increases, that is a good indication that your T levels are coming back to normal.