If you use under 8mg I bupe in one day, you can still feel your heroin, not as much but you can. Anything over 8mg expect blockage, however I busted through 16mg of bupe before . The reason why that Tiny little piece of bupe blocked all your heroiin is because you did the two TOO CLOSELY togethor. Usually after a few hours you would be good to do the heroin, since you did them back to back you got blockage. As far as sweating and feeling like shit, I can't explain that, but the only way you will feel sick (precipitated withdrawl ) is If you do heroin and THEN use bupe. The other way around will only diminish the effects of opiates or block completely. So remember next time never to heroin immediately after bupe regardless the dose cause you will get blocked, if you wait a few hours, you can still feel the heroin depending how much bupe you previously took..
Point is don't expect to enjoy yourself with bupe in the mix...I been through it..