MY best wishes, Heather!

Try to realize that you have done all you can at this moment; and then direct your thoughts to some completely different topic that would ordinarily occupy them if you weren't concerned about the lump.

It could well be benign, but since the usual human tendency is to focus on the worst possible outcome, thoughts usually go in that direction if you give them a chance. Since they are your thoughts, take charge and direct them away.

If you do this, and you can, you will save yourself a lot of un-necessary and un-helpful mental anguish.

I've read that the Chinese ideogram for "Danger" is the same as for "Opportunity." Use this to your advantage; when you need a place to direct your unbidden negative thoughts, use this opportunity to direct them to taking an inventory of those things that you love and/or enjoy in life.

Be aware that life only exists in the moment. The previous moments are all gone, never to be repeated, and the next moment is uncertain. People drop dead for no apparent reason all the time, and none of them expected it. So, this moment is the most precious in your life because you HAVE it. DO NOT miss this fact, or you will be missing life when you need it most.