I have been sitting on and off for about 17 years and have had a couple of, for lack of a better word, openings. After the last one in '08, where i felt i saw my true context in relation to the rest of the universe, a chan teacher assigned me a huatou. So since then, as far as my meditation routine thats about all i have been doing. The last couple of days tho i tried something new, just sittting on the cushion and letting go of everything i could let go of, surrender.
The last two times i tried this, yesterday and the day before, i got very pleasureable bodily feelings and some nice clear headspace, it was great really. I felt on the verge of some sort of break through. Today tho im feeling drained physically, enough so that i couldnt finish my workday.
My question is, should i continue with the letting go practice? Should i try to pace myself with it? Im not sure pacing myself is an option really, its hard to let go a little bit

Anyway, anyone know how to place this experience or if its a good idea to continue with this kind of practice? Thoughts please?