XANAX VS HYDROXYZINE???

Hi so I was on Gabapentin and started having trouble breathing. It slowly got worse and then I had a panic attack... i had never had one or any sign of anxiety in my life. For a week after I has bad heart palpitations, Nerve zaps/ muscle jerks, and it was painful to sit still. It has subsided but is still there everyday and is painful to live with. There is definitely something wrong. So I was prescribed HydroxyZine by one primary and I went for a 2nd opinion. I was prescribed Xanax .5 by the newer primary and he said he believes I developed GAD(General anxiety disorder) from the Gabapentin which works on receptors and central nervous system. I have never taken many meds or gotten high. Im probably hypersensitive to meds. Hydroxyzine is a antihistamine. But my doctor said xanax is better as antihistamines could sometimes make you feel wired... Im a care of meds because of what the gabapentin did to me. I have been off it almost 2 months... and still have problems so it triggered something. I need to know if that .5 Xanax is safe and if anyone thinks jt could be effective for my problem please. And if so how often should i take it only for a short period if 2 a week or 2. My symptoms from the gabapentin are hear palp, muscle jerks, FULL BODY NUMBNESS everything feels dull, heavy head/headache. -THANK YOU!!