It's good that you're taking a pro-active approach to trying to fix your problem. I'd love to help. I think first, however, it would be ideal to have a little more background information. What are your smoking patterns? Where do you usually smoke? Do you notice any pattern to when you start having a bad trip? How do you react to these problems (the numb-mouth, etc...). Does it throw you off at that point or (since it's after 1-2 hours) do you think it's a side-effect to the weed?

Dude