Hello MZ and welcome!
I am sorry to hear of your increased anxiety post-op...
..but glad to hear that you are getting the help that you need for daily management, and that you've reached out here.
Well done.
You are right in that during a start up, anxiety can be increased temporarily, so what you are experiencing is normal and will phase out soon.
As far as your heart rate, this is usually something you see more when taking a beta blocker rather than an SSRI...but everyone can have their own unique reaction to any given Rx.
Since this is bringing you into a more healthy range as far as pulse goes...I would consider this an unexpected benefit as long as you are being monitored by your doctor, and he/she sees no need for concern.
Post anytime with us for sharing and support. Please also see our Resources at the top of our main forum page here for great self help material. Practicing the suggested exercises such as from the 'Stress Relieving Exercise' link and the Meditation Videos will lower your overall anxiety, and help you to feel your best.
Talk soon,
Scaredy Cat