Hi @cdc43, Welcome to Connect. This discussion hasn't been active lately but several members in the discussion may have missed your post. I'm tagging them here to see if they can share any more information with you.

@kenc mentioned the pain under the big toe nail turned out to be caused by a fungus in the post above yours.
@jeanniem had an appointment setup with a podiatrist and may be able to share the cause of the pain.
@miker8888 recommend seeing a Board Certified Podiatric Surgeon. I had major pain in big toe due to calcification of joint. Surgery helped tremendously.

Have you seen a doctor or podiatrist?