I started xanax for the 2nd time-stupid thing to do

I took Xanax 15 years ago. Was on 3mg a day for years. I finally managed to taper off using diazapam. I got Covid about 3 weeks ago and had extreme worry and fear about it. I just got over it. Stupidly I had some emergency xanax I always kept around for panic attacks. I started taking about a .5 tablet every day that I had covid and up to now, about 3 weeks I've been taking it. I thought I could just quit no more or longer than I had been taking it. Yesterday it through me into a horrible all day long major panic attack. I need some support and understanding.