Based on what you are reporting here, I would definitely agree that you have an anxiety disorder and not schizophrenia. Anxiety Disorders can be very severe and debilitating, and can sometimes be brought on by drug use. You reported that you have always been a worrier so it was probably lying dormant and smoking marijuana may have helped it manifest. You have mentioned trying medication to treat your anxiety but you have not mentioned therapy. Medication alone is not always enough, especially relying on ones like Xanax that are best used for acute issues such as a panic attack, not long term use.
I would suggest that you begin working with a psychiatrist and a therapist and stick with them both. You could look into seeing a sleep disorder specialist and since you reported that you felt better while pregnant, you might also benefit from seeing a hormone specialist for some testing in that regard. Many times it is necessary to supplement your medical treatment with exercise, relaxation techniques, yoga or meditation. I hope you feel better soon and can fully enjoy your family.
All the best,
Dr. Holly Counts