Nacho,
Your description reminds me of the description
of spiritual dryness. I think St. John of the
Cross called it The Dark Night of the Soul.
There is another name which I cannot find
right now like asadea: Someone else may know.
It sounds to me as if you are going through
a spiritual passage. SFQigong is many things;
one of which is a spiritual practice.
I can only encourage you to continue the
practice as best you can. It may be just
doing one of the meditations or one small
active exercise of your choosing until
what you are going through lifts.
You might put yourself in the group
healing.
Gianni