I can sympathize with how you feel. I once found a lump - on a Friday at midnight, too. That turned out well but it gave me quite a turn.
Can you look at your tonsils? How about the gland under your jaw, one on either side? Your throat is what colour? And, I think it's the glottis, that little pink thingy at the back of your mouth, is it swollen (rounded instead of pointy)? Is the problem symmetrical?
I mention these things because they go wrong with me and when they do, they can be cured with penicillin.
But of course you'll have to get it checked.
Well, that night when I discovered a lump I didn't sleep at all. I knew I wouldn't sleep, so (being an optimist) I wrote out my Will. I began with 'books to sis, music to nephew' and then realized i had nothing else anybody would want. And also that it isn't nice to bequeath credit card bills. So I changed my Will to a warning that my family should refuse to inherit.
That being done, it was only about 2am. I had an Alfred Hitchcock Mystery Magazine. It had a Mystery Photo Contest. I can write, but it was sort of established in the family that i can't write fiction. But I tried. And I wrote a story and a zillion rewrites, finished it just after sunup and fell into a contented sleep.
Do you think you'll sleep tonight?