Ummm, I dunno about the 120 vs 130 discrepancy but the 2x bhang bars are 120mg TOTAL, 30mg per serving, read the back. The pic you posted and the bar I have in front of me both say 120 and have the same labeling.
PS> If you avoid fats and start drinking water at the onset of an uncomfortable high from edibles it will bring you back down.
PPS> If you stop freaking out when you get that high and chillax, you'll really enjoy the ride. I WISH I could get that high anymore. As far as edibles go I usualy go 200mg+ per serving, the cholates I just made are somewhere in the 300-400 range each;
https://www.rollitup.org/cooking-cannabis/768530-companion-cube-peanut-butter-bho.html