what does the bong look like, is it clear? if so i dont see how the bong could be adding to what your inhaling (as in ud be able to see anything foreign in the bong)

maybe u shud try washin it in rubbing alcohol and salt, and dish detergent for good measure.

(if cleanliness isnt the problem) are you familiar with the weed your getting, are u sure u can trust it, bc it sounds like u got ur weed laced