At times, I feel like energy is going out of my head. I don’t understand what is this.
You do not mention when you experience this energy but since you have asked your question on our site which is dedicated to spiritual topics I am guessing you experience this energy during a spiritual practice such as meditation.
I think it will help to understand the subtle energies in our astral or energy spine. We have seven energy vortices called chakras in our astral spine. You describe experiencing energy at the 7th chakra at the top of the head. In meditation practice we seek to lift the energy in our spine up to the point between the eyebrows called the ajna chakra, spiritual eye, or 6th chakra. It is at this point that we can enter into union with God. We awaken the energy in our astral spine through yogic techniques, which include meditation, hatha yoga, and pranayama. When energy goes directly to the 7th chakra as you describe, it may cause an imbalance. Thus Yogananda, our guru, trained devotees to concentrate at the 6th chakra directing the awakened energy to that point. When the energy is concentrated there a subtle channel opens between the 6th and 7th chakra and the energy rises to the crown chakra.
I encourage you to look at information about the chakras from a long-time Ananda member, Savitri Simpson, who has made an in-depth study of this topic. You can read about this on our website here.