If you are on the dean's list it would appear that you are coping very well. Why introduce an unknown into your life that may disrupt it? The medications you are thinking of are not without their dangers, and not everyone reacts well to them. On this forum, over and over again, we hear of patients who have switched medications and dosages repeatedly, looking for the right balance. You are assuming a pill will be some sort of quick fix. It might not be.
As an adult dealing with ADD, its always important to learn coping skills. And if you do want to become a doctor, it will be even more important later in your life. So the idea of seeking additional help from the people your psyc recommended is worth while. It is also possible that after meeting with them they may realize that meds are necessary for you and speak with your psyc.
You might also want to talk with a counselor in your college. The University of Texas is a huge school. I would think that they have experience with students with ADD. They probably even have a psyc on staff who might be more responsive to your needs. Good luck!
You seem to be doing really well without medication. I'm not really sure why you think you need it so badly. Like all things, it also has undesirable side effects and many people don't desire medication if they don't have to take it. That might be what is concerning to a physician. There is drug seeking behavior that doctors look for. I don't think your revelation about prior marijauna use is impacting things as much as clearly you've developed coping skills for add but still seek medication.
Did you go through an entire add/adhd evaluation and have a firm diagnosis?
I would try therapy with the professionals recommended to you as you may indeed find it helpful and learn even more coping skills than you've already aquired.
good luck