What Causes Anxiety Attacks Along With Tremors In Hands?

I am 42 yrs old and for the first time I have anxiety attacks. I am very aware what I feel and it gets worst because I am usually in control of my life being a single mom. It makes it worst where I ended up in the emergency room. I am experiencing intended tremor in my hands. I am on clonazepam 2mg. I take half in the morning and half at night. I am have taken Zoloft but it has not helped. I was changed to wellbutrin to 100 mg once a day. My anxiety has gotten a bit better but i am aware of what time it is thru the night. should i go back to Zoloft?