While you’ll likely make a full recovery in time, your initial goal is to limit the pain and inflammation. You’ll want to stop yourself from any unnecessary thumb movements, use the De Quervain’s Wand and De Quervain’s Tape regularly and consider over-the-counter medicine like ibuprofen or naproxen.
If these more conservative treatment attempts do not make a difference, a steroid injection is the next course of action. Ideally, if administered within 6 months of the first symptoms, the problem will resolve.