There are alot of runners that get the baton in the 4 x 4 and feel they have to run like you say you do because of their adrenaline rush. That's just something you have to work on; running your own race.
Yes staying on your toes is extremely important.
If you have been doing tempo workouts since the beginning of December then you need to move to something else. Something faster. Your body has now become adapted to your workouts. You should only do intensive tempo work for 4 weeks at the most. Anymore than that is overkill.
Try doing some split runs or some depletion runs or maybe even some Special Endurance type runs. You should see some improvement in a few weeks. Also, read some of the message boards here at elitetrack.com, you'll find alot of helpful info. Lookup 400m training in the elitetrack search engine. Also, check out 400Stud's message board on his training and my message board will help you out alot also. Both are found in the training journals section. Good luck with your training. And if you need any additional help, let me know.