Well, not to one up you, but I've had slot more than 70 and that has destroyed my tolerance. But how long it takes for a roll to REALLY hit you depends mostly on how soon you ate prior to taking your tabs. If you don't have anymore to rebound, try smoking just a bit of weed (like three hits). That usually jumpstarts my roll. But don't smoke too much or it will blow your roll out. It also seems like you are thinking about your roll too much. If you anticipate your roll, you won't get it. Try starting a group conversation or playing a game. Once you forget about the roll, you will usually get it
good luck, hope I could be of some help