Week 4 on Zoloft and I've had panic attacks each day. Please help.

So basically last month I transitioned off Prozac (too many side effects) onto Zoloft as such:

Week 1: 25 MG
Week 2: 50 MG
Week 3: 75 MG
Week 4: 100 MG

The first 3 weeks were fine. Didn't help so much with anxiety (which is why I am on medication), but the side effects weren't nearly as bad as they were on Prozac. I figured I just had to give it time.

However the last week when I've been on 100MG I have had severe panic attack every afternoon. Each getting worse than the last. I've had panic attacks before, but this is the first time where 1) there are physical symptoms [my heart is POUNDING] and 2) they are much longer. For instance yesterday I had one that lasted nearly 4 hours. It was insane.

Does anyone have thoughts/advice? I'm seeing my psychiatrist today. I really want this to work, but idk. Maybe I could go down a dose? I have a really important week next week at work and I cannot be freaking out 24/7.

Thanks