Help Stumped trying to find carotid artery

[imperfectcircle]

I apologize if this has been asked a bunch, but I'm just frustrated. I've been trying for 2 days now to find the sweet spot of my carotid arteries. I know that your vision is supposed to turn black, but the only experience I've had is lots of pressure in my head and headaches afterward. I tried looking on the night night thread, and using those suggestions, but man I just cannot find it. I've tried sitting up, laying down, closer to the front of my neck, the sides of my neck, under my jaw. I got close once and my vision STARTED to blacken, but it stopped, and I haven't been able to recreate that since. Any tips? If it helps I am a thin female, my neck is pretty slim. What exact specific hand placements should I try? This is really frustrating me and just making me want to self harm more lmfao