Bactrim DS Anxiety Panic Attack, Normal Blood Pressure, Soles of My Feet, Short of Breath, Benadryl

7 hrs after 2nd dose my palms and the soles of my feet started itching like crazy. I did not make the connection. 20 minutes after 3rd dose.
I was at work doing charting, at some point I must have been in a fugue like state because it slowly started to dawn on me "I'm sitting in a chair" "I am at work" "I am not sure what I was just doing" "Something is really really wrong". Then I realized my face was numb, my heart was racing, I felt short of breath, my whole body was tingling, my ears were making this buzzing noise. Then I started shaking so hard my teeth literally started to chatter. My legs felt like jelly, my hands and feet were ice cold, I was having difficulty talking as some of my words were slurred. I kept needing to urinate (I am talking huge amounts) and I had this intense feeling of worry and my blood pressure was 170/96 and then 190/101 (I am somewhat hypotensive, a normal blood pressure for me is 90/58 if I am really stressed my systolic may actually make to 105). I immediately took 75 mg of Benadryl. It turns out I am sensitive to it and it has basically caused an anxiety, panic attack disorder. I have NEVER had anxiety issues before. It has been 12 weeks and I just weaned off of the Paxil, though I am still using xanax for the panic attacks (the are slowly decreasing in length and intensity. It took almost 2.5 weeks to figure out it was causing this and to get on meds for it. Until then I kept going to the E.R.