go to the doctor, and be upfront with your marijuana smoking - if you're going to be prescribed meds to change your brain chemestry, your doc needs to know everything you're on, including herbs and supplements.

effexor has been a great help for me, because in addition to increasing serotonin levels (to make you less depressed - this is what prozac, paxil, etc do), it also acts on norepinephrine, which increases motivation. i can go into way more detail on this if you like.

xanax and ativan are often prescribed for panic, and they help, but it's important to include therapy to learn how to deal with them. try to find a cognitive behavioral therapist; they will retrain your brain. remember: when you're having a panic attack, you may feel like you're going to die, but you're NOT. remember to BREATHE. a panic attack will not physically hurt you, and it gets better after you really, truly understand that.