1) "However, after many years of practice, I was able not only to do this asana, but also move on to Eka pada sirsasana, Dwi pada sirsasana, Yoginidrasana, etc." (parallel structure)
Use: but also to move...
2) "for long time" (missing article)
Use: for a long time.
3) "I heard many people say that yoga is very boring, you sit there and breathe. " (common splice)
Use: I heard many people say that yoga is very dull; you sit there and breathe.