Wow 42!Where to start with this! When I was in elementary school I had a friend whose parents told her she was stupid, etc etc when she did not get the grades they knew she was capable of! NOT a good way to handle it, but maybe that is the way her parents were raised. I am thinking maybe it is the same way with your parents. I am not saying they are right for treating you that way, I am just trying to rationalize their behavior. Maybe if you think about it that way you can deal with it a bit better. The psych at school can probably give you some really helpful advise, whether you are smoking pot or not. The psych and help you learn to deal with all the guilt trips and put downs your family lay on you. But it is always better to be honest, so stop smoking!
I am not going to condone your use of pot....but I can not give you a hard time about it either. The thing that scares me is that pot is a gateway drug and you do not need any more problems. Even though pot has temporarily made you feel better, look at the problems that have come from your use. Seriously, spending so much money on your moms card! You know you will have to come clean and take the punishment! And it will not be a pretty scene since you have lied over and over. Please do not think I am judging you, I was no angel in H.S. but think about all this. I do believe you are very intelligent. So put those smarts to work. You know that you are not responsible for your Grandfathers heath. Logically, you must. You can not carry the weight of your family on your shoulders!
Good Luck 42. I will be thinking about you!!!