I have been practicing rigorously, but lately I feel that I’m not evolving. Why?

Doing easily becomes a ritual. You will be chanting, but your mind will be musing on other matters. Evolution is not possible this way. Conscious efforts happen only as long as it takes to learn a mantra or practice. Then the sub-conscious takes over. It becomes a ritual. Conscious mind does not need to bother anymore. There is no evolution in this process. This is happening to most people. If we do not know exactly what we are looking for, we keep searching unconsciously and will not find anything. The remedy is conscious Sadhana or practice.