Hypnosis side effects?

Hi! I am trying the Nerva hypnotherapy app for IBS as recommended by my doctor. I feel like I am very bad at being hypnotized though. I have trouble settling into sessions. And am very easily pulled out of the session by the slightest noise or even my own stray thoughts. And frequently, I will reach a point where I start to feel incredibly anxious. My muscles twitch unpleasantly and I feel like I need to peel my skin off and run away from this intense sensation. I was wondering if anyone else has experienced this? I have a therapist who once mentioned that I would have trouble meditating due to some PTSD in my past. I am curious if my struggles with hypnosis stem from the same issue. Any thoughts or ideas? I’m curious to know if anyone else had had a similar experience. I haven’t found anything scientific using the googles. Lol