I am unsure if I have a drug interaction or if I have new manifestations of A-fib symptoms.

I had an ischemic stoke in April and was diagnosed with A-fib. Just before that my Dr. put me on Zoloft (a change from Celexa). Here's the timeline.
March 15 started Zoloft
April 20 my first episode (details below)
April 29 stroke (minor & recovered)
May 6 put on Eliquis
Since then I have had 3 more episodes.

Symptoms of episode;
Sudden onset
Sever dizziness
Hot red skin & sweats
Nausea
Symptoms last about an hour & subside after 5-6 hours.
Question, A-fib or Zoloft?