What am I doing wrong in interviews? Looking for honest UK job-hunting advice

I’d really appreciate some honest advice from recruiters, hiring managers or anyone experienced with the UK job market, because I’m trying to figure out where I’m going wrong.

A bit of background: I’m currently doing a Master’s in Digital Management in Scotland and have 10+ years of experience across digital/QA, marketing and consulting.

Academically, I’ve been doing well, with Distinctions in my modules so far, and I’ve had great feedback from my lecturers. A few people I’ve worked with have even said they’d like to hire me once my visa situation is sorted.

My visa situation will also change soon. Once my results are out, I’ll be switching to a partner visa, so I won’t require employer sponsorship.
The frustrating part is that I do get interviews, but the jobs I genuinely want are the ones I don’t seem to get.

I understand the STAR method and use it when answering competency questions, but I’m starting to wonder whether I’m using it too obviously and sounding too rehearsed rather than conversational.
I’m also curious about body language. I naturally use my hands a lot when explaining things. Could that come across as nervous energy, or is natural movement generally fine in an interview?
I prepare a lot, but once the interview starts, I sometimes focus so much on giving the “right” answer that I lose some of my natural personality.
So I’d love some honest feedback on anything I might be missing like preparation, nerves, STAR answers, body language, communication style, confidence, or simply how to come across as someone you actually want to hire.

I’m already nervous as I have my interview tomorrow 🙈👀