I was previously treated for extreme anxiety and panic attacks with mirtazipine 15mg and diazepam 10mg and worked perfect but got relapse 2 yrs later?

Time to see doctor: If you had good results previously but now have relapsed, it's time to see your doctor for sure. Some adjustments, changes, or additions can be made so that you can feel better. Also, psychotherapy is an essential part of recovery from anxiety -- and of its long-term management.

Question not clear: Though your question is not clear, I have some information for you. The combination of medications was effective for your condition. Though not approved for panic disorder, or even anxiety, and not even for ptsd (post traumatic stress disorder), mirtazipine has been used off label for ptsd. Diazepam was probably the first really effective medication used for acute panic. This disorder reoccurs.