Try to pace yourself. Use the time to your advantage. For quant, be careful with tricks. I would rather double check the question every time before I move on than finish ahead of time. If you are sure you have plenty of time, relax and rest your brain.
For verbal, you have to be focused. You should be glad that you treat the mock test as real one and now know what your problem is. Work on one question at a time. Develop your own approach.