Carrying power through rounds!

The first thing that I would recommend, as it's the most logical, is just to keep sparring. The more you understand your body when put into that situation, the better you can control your output and the overall condition of your body. The next thing is to train with more intensity. I was once told that if you want to get your body in a certain condition then you must put yourself in a position where your body has to adapt to survive. In the process, your mind will bend around it. Lastly, if you're going to train like an animal, get lots of rest. It helps your body recover and keeps your mind sharp. Understand that all physical activities suffer when fatigue sets in. During sparring is even worse because the guy in front of you is still coming so fear and doubt tends to seep into your mind which leads to hesitation and further degradation of your mechanics and overall awareness/ skills.