Welcome, Inedible, to the forum, and thanks for posting your questions and comments. Clearly the phenomena that you described indicates you are meditating deeply. So, I am glad you are keeping up your practice. The biggest conflict most people seem to have when they come here is the guidance in meditation that they received before coming here was very amateur. Sadly, I cannot think of a single book on meditation that even refers to, or understands depth in meditation.
So, to begin with, you are clearly getting lots of piti and sukha, which are the first stage of jhana/samadhi. The next thing to understand is you are not going to get anywhere until you still your mind, and stilling the mind means your meditation technique needs to be dumped at which time one simply attends to maintaining the still mind, and the arising phenomena that you described, and much more.
Since you seem to start falling asleep as soon as you start to meditate, it sounds like you are ready to zip out-of-body, which is good. I would suggest that you try meditating lying down, instead of sitting up. Please let us know how that works for you.