What kind of doctor would I need to get tested for adhd?

Psychiatrist. A psychiatrist can do an evaluation for adhd.
Start with your doc. People perform their best when well rested, properly nourished, in good health & a comfortable setting. These are also components that must be part of a baseline evaluation for focus disorders. Your doc can help verify your state of health & review your sleep symptoms. A sleep study may be needed. If the basics are okay they can refer you to a psychiatrist for the rest of the evaluation.