You are currently taking an antibiotic-antiprotozoal combination, a medication for nausea, and an antispasmodic. While these target infection and stomach cramps, the most critical step for severe watery diarrhea is rehydration. Please start drinking Oral Rehydration Salts (ORS) immediately to replenish lost fluids, especially before you travel. For your headache, a simple paracetamol tablet is safe to take. While traveling, avoid street food and stick to safe, easily digestible options like bananas or curd-rice. Since antibiotics are not always necessary for watery diarrhea, please consult a healthcare professional nearby to evaluate your condition and ensure a safe journey.