Black spot/skin on tonsil. Solution?

Hi, there appeared to be a small black dot/skin on bottom edge of my left tonsil which still remains for last 3 months now. Although it is a small one but the black colored area appears to have grown slightly. CT scan (with dye) had shown 'normal' results. I have seen three ENT doctors so far - whilst they have advised it's NOT cancer, but none of them are able to confirm why this black spot has appeared on tonsil! This has been causing me extreme anxiety as I see it in mirror each day. Note: the black colored spot almost disappears (back to normal skin) in the morning but gets darker later in the day. Can anyone please suggest what this relates to and whether I should continue worrying? I am thinking to get both my tonsils removed- will this be a better solution? Please help. Thanks