Hi NTC,
When I read your words, I sense the fear you have. There are a few other things that stand out to me.
You've had several doctor's checks and an MRI that came back negative. You've obviously been poking around in the area of concern as you've developed the ability to reach down your throat! This is an ability I'm pleased to say I don't have! Poking a prodding an area like that certainly can aggravate things regardless of an issue.
You obviously have worked yourself up into believing you have cancer and you've not been diagnosed. I suggest you stop sticking your finger down your throat, take a deep breath and calm down. It's not cancer until they say it's cancer!
I truly understand your fear as mine came true BUT you've not been diagnosed and all the doctors thus far feel there's nothing to worry about. That's pretty positive in my opinion! Make an appointment with your doctor and express your concerns. The only way to truly diagnose OC is through a biopsy. However, if there's nothing to biopsy then sooner or later after getting the all clear from medical professionals, you're going to have to find a way to trust what they're saying.
Good Luck, positive thoughts and prayers.
"T"