Dear Mazefish,
Working with "contracted" areas as you find them has resemblances to Goenka-style sankara releasing, as well as just tuning into the suffering characteristic, which some describe as contractions or tensions. That you notice these tensions come and go has aspects of noticing impermanence, which, along with suffering, is one of the Three Characteristics, the last one being no-self, which you also mention as you state that, in noticing tensions come and go, you also have less of a sense of self. So, what you are doing seems to be some variant of vipassana, albeit with your own twist on it. Vipassana leads to the stages of insight, found in a number of sources, but I tend to reference my own descriptions, found in Chapter 30 of MCTB2 found here
www.mctb.org.
Practice in daily life is a good idea.
As to emissions, that is more of a Daoist/Taoist concern, and I will let those who know more about that tradition fill in if they wish. You can find all sorts of discussions around that topic on sites such as the
Dao Bums.
Hope that helps.
Great beginner book on meditation: Mindfulness in Plain English, by Bhante Gunaratana.
Best wishes and practice well,
Daniel