So medical grade microchips are a technology that is in the process of creation, but it's not a working technology yet. There hasn't been a way to make a microchip safe to be implanted in the human body. You can't just take any silicon chip and put it in a human. That's not something a body can tolerate safely.
Also to put something in your neck, as said, that's a very dangerous medical procedure. There's no way someone like a hair stylist could do that to you while you were awake. You'd need actual surgery and trained medical professionals for that.
Further, there's no ethical way at this stage that something like that could be done to you. As far as I'm aware that technology still hasn't even hit the animal testing stage yet.
I know the thoughts and feelings are likely not fun to sit with or try to challenge, but what you are describing just is legitimately not possible based on the current limits of science or medicine. Your feelings are absolutely valid though.
Please let me know if this is upsetting and I will delete it. I'm glad you are getting back in to swimming!!