Modafinil causes alertness and decreases sedation. While Alprazolam increases sedation. Both have opposite actions.
Modafinil will decrease the level and effects of Alprazolam by altering drug metabolism.
So combination of these drugs is NOT good.
Apart from this, Alprazolam is habit forming drug. It is not advisable to take Alprazolam for long time.
Next Steps
You can try Cognitive Behavior Therapy for Social Anxiety Disorder.
For more information on Social Anxiety and Cognitive Behavior Therapy kindly consult online.