How do I stop the physical symptoms of anxiety?

Hi everyone, I’m looking for some advice or insight because I’m honestly pretty confused.

Since the start of 2025, I’ve been having these random “episodes” where I suddenly feel really unwell: I need to rush to the toilet with diarrhoea, then I get shaky legs, chills, sweats, and sometimes it feels like an intense wave of panic even though I don’t feel mentally stressed beforehand. They come out of nowhere and I can’t find a pattern.

Because I have PCOS and coeliac disease, I went down the physical-health rabbit hole first. I’ve had blood tests (including iron), checked for things like POTS and Mast Cell Activation Syndrome, and everything comes back normal. My vitals are always fine. I even wore a Dexcom blood sugar monitor for a week and my readings were totally normal.

At this point I’m starting to wonder if this is all psychological/anxiety-related, but the confusing part is the lack of obvious triggers. These episodes don’t always happen when I feel anxious, they often cause the anxiety, not the other way around.

Has anyone else dealt with physical symptoms that appear completely random? How did you figure out what was actually going on, and how do you stop or reduce episodes like this?

For extra context: I’ve been on sertraline (an SSRI) for about 5–6 months but haven’t found it very helpful. I’m going back to the doctor next week, but I wanted to hear from people who’ve been through something similar about what steps helped you.

Thanks in advance