It is recommended to seek medical advice for persistent and severe mouth ulcers, especially if they are impacting your ability to eat and drink. A doctor can provide a prescription for a specialized mouth rinse containing antibiotics, anti-inflammatory, antifungal, and possibly anesthetic properties to help improve the situation. Over-the-counter options may not be sufficient in such cases. It is important to address these issues promptly to prevent complications and alleviate discomfort.