Hi. Most of us are in the US, but I am assuming you're having trouble with your GP? Do you think you have sleep apnea, but they won't approve you for testing? You could try seeking a second opinion from a different GP, writing a letter to the practice manager, or going private if you can, but I know that's not always easy.
Have you considered bringing a family member with you to talk about your symptoms? Or maybe taking a recording of you snoring/gasping? You might also look into monitoring your oxygen levels while you sleep -- some devices connect to your phone, which would give you data to share with the doctor.
I'm sorry that you don't have the freedom to get tested when you want to on the NHS. Keep advocating for yourself, I hope you can find a way forward soon! -Melissa, team member