Hello,
I recently came back from my first retreat, a 9 day retreat at IMS. Not much was discussed about the territory of experience, so I would like to understand where my experiences land in the map as I have a tendency to inflate

I am new to insight practice but have practiced kriya yoga and meditation somewhat steadily for three years.
So to get down to it:
My predominant experience on the retreat were intense bodily sensations and pain on a level much deeper than my ordinary experience. Tension in the face and throat migrated down to the chest (worst pain I had ever felt) and into the spine where it stayed for some days as I worked with the hindrances surrounding it. Later on the pain continued down the front of my body through my groin and down the inner thigh. Tension in the back would release and I would shake like a dog trying to dry itself. At times my body was pulled into different postures. By the end of the retreat (and continuing afterward) I the hindrances were still coming, but I could clearly note them without identifying.
Off of the cushion I would cycle between frustration, irritability and doubt coupled with the experience of deep relief in my body, emotional release and a gratitude for life. My energy body's completeness grew, especially in the chest, pelvis and legs. The acuity of my senses increased and I experienced partial relief from physical ailments that have been troubling me for years. (Yes I know this is a story

So my questions are as follows:
What stage of practice is this, and how should I proceed as this physical process continues? Can I expect it to heal me? One of the questions that was not answered on the retreat is how to relate to pain when I have a habit of pushing myself, whether to deeply investigate the pain or to note the habit of "prying" or "pushing."
Another question is, where does the heart fit in to all of this? The teaching on the retreat emphasized the heart opening to experience with equanimity. Since the retreat I have definitely felt a lot more love for myself and others, but can't help noticing that it doesn't seem to be mentioned much in my exploration of this website. (Admittedly this is pretty limited)
Finally on a side note, if anyone has experience with more hindu forms of meditation (like kriya yoga and hindu tantra) could they please explain the difference in the term "samadhi" between these and buddhist meditation? The meditation teacher I first learned from (a sort of amalgam of kriya and tantra) postulated samadhi (first savikalpa then nirvikalpa) as a goal of meditation, defining it as a state of oneness, bliss, and nothingness when the meditator's energy reached and emerged from the crown chakra. This does not seem to me to be the Buddhist definition of samadhi, so any clarification would be appreciated.
Many thanks,
Ben