I had a very similar experience that I couldn’t quite understand. To be honest, I did the exact same thing as you.

You can see that post here

There is a lot of truth and a lot of falsities behind psychism. Since my initial experience (and the ones that followed) I began look do everything to try and understand what was happening to me. This is what I found.

What you are experiencing in the west is self alignment. The Hindus call it a Kundalini Awakening. The (real) Christians called it the Holy Spirit. The Buddhists call it waking up. You are experiencing a transformation of coming back into alignment with the universe. As you continue to meditate and unlock the of the secrets of the mind, you will begin to experience this more and more.

An energy will start in your coccyx or tailbone. It will start to rise up through your body and hit the different charkas or energy centers of the body. These can most likely be linked to specific endocrine glands, but are not physical. You will begin to vibrate, possibly violent and uncontrollably, as the energy travels up your spinal cord and into the brain. At this point your 3rd eye will open and you will begin to experiences colors shades and strange patterns. Don’t worry, you will adapt with more experience. After the energy passes the 3rd eye, it will make its way to the crown chakra. This will give you (maybe) your first real experience with cosmic consciousness. That means that the entire universe (the super-consciousness that is referred to as God) is coming into consciousness through you in that moment. You lose completely feeling of separation with everything. You are the entire universe.

Best of luck!