A little setup:
This is a Chapter 4. Scott's grandfather just died. A man named Penn promised lots of money in return for an urn that he retrieved from his grandfather's house. Scott had no idea foul play was involved.
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Aunt Flora confessed the day after Scott returned to Richmond. He didn’t believe it for a minute. She’d never poison Grandpa. Never. He’d hire a good lawyer. Once he had the money for the urn...

Scott slammed the phone down. For five days, Scott had called the number on Penn’s card. Nobody answered. Not even a machine.
When he rose from his chair the desk swayed. More lightheadedness. Three hours until another headache, he figured. Dizziness. Headache. Dizziness. Headache. Six days in a row. Annoying, but nothing like that first day.

"Aunt Flora confessed the day after Scott returned, and he didn’t believe it for a minute."

I'd cut this:

"Scott slammed the phone down. For five days, Scott had called the number on Penn’s card. Nobody answered. Not even a machine. "

"Annoying, but nothing like that first day." can be changed to and affirmative statment. "The first day was the worst."

"Pills didn’t seem to help. Lyn would’ve insisted he see a doctor. Had he told her. Doctors were for the sick and sickness was for wimps. Anyway with time, it’d pass. Like most things."

There is something you can do to put the Ideas together:

Pills didn't help, and neither did Lyn.
"You should see a doctor," she said.
"Doctors are for the sick and sickness is for wimps. It'll pass," Scott said, like most things.

It's mostly a style thing. You can keep it as is and there wouldn't be a substantive difference.