White patches on the tongue that are not improving with antifungal treatments like Candida mouth paint may not be simple fungal infection (Oral thrush) and could be due to conditions like Leukoplakia, vitamin deficiency, poor oral hygiene, or even irritation from smoking, spicy food, or acidity; the feeling of thickness and persistent patch needs proper examination. You should maintain good oral hygiene (brush tongue gently, rinse after meals, avoid tobacco/spicy foods), stay hydrated, and most importantly consult a dentist or ENT specialist soon for direct examination