Hi Sammy, Paxil is a well known and established medication for panic disorder, but it can mess with some liver enzymes that break down other medications. It's not a problem with every medication, but it is something to keep in mind if you ever start another medication. Always make sure to tell every doctor you see (dentist included) that you're taking Paxil. Most of the time they can work around it by giving lower doses, or giving another medicine. Out of the SSRIs, Celexa has the least potential to interact with other medicines because it doesn't mess with liver enzymes nearly as much as the others. Zoloft also has less interactions, but you already tried that med with ill effects.
Personally, I've found Celexa to be the most gentle of the SSRIs and very effective for anxiety and panic. Paxil made me feel a little too sluggish and gave me dry mouth. This, however, was my experience, you may love Paxil. No two people are the same, what works for one may not work for another. But I will say, that out of the SSRIs, Paxil and Celexa are the least stimulating. Lexapro is pretty much the same. It's a supposedly cleaned up/ less side effect version of Celexa, but I've never noticed much of a difference between the two. In fact, I felt that Celexa worked better for me. But as I've said, everyone is different.
This is just my 2 cents, every decision should be made by you and your doctor.