It sounds like cannabis just may not be the drug for you. Most people just get high and have a good time, but there are always those with weired reactions, like my mom and sister who get freezing cold and depressed when they smoke (hence why they don't). However, I used to feel kind of "off" the day after smoking as well, making little mistakes and the such all over the place. But once my tolerance got way up I don't find it's affecting me at all the next day anymore, and I'm still going through college quite successfully. Do you really have an intense psychadelic high when you smoke? I used to for the first year and that's when it was impairing.