It sounds uncomfortable to deal with chronic gastric issues, neck and shoulder stiffness, and acid reflux together. Managing these symptoms often involves addressing stomach acid and muscle tension while ensuring proper diagnosis.

• For acid reflux and gastric discomfort, medications like Famotidine (found in Famocid 40 Tablet) can reduce stomach acid and help heal inflammation. However, this should be taken only under a doctor's prescription and guidance.
• Neck and shoulder stiffness might be related to muscle strain or posture issues; gentle stretching, heat application, and ergonomic adjustments can help, but persistent stiffness should be evaluated by a specialist such as an orthopedist or physiotherapist.
• Lifestyle changes can support symptom relief: avoid spicy, oily, and heavy meals; eat smaller, frequent meals; avoid lying down immediately after eating; and maintain good posture.

If symptoms persist or worsen, it is important to consult a gastroenterologist for your gastric and reflux issues and an orthopedist or physiotherapist for the musculoskeletal symptoms to get tailored treatment and investigations. If you experience severe chest pain, difficulty swallowing, or breathing problems, seek emergency care immediately.To narrow down potential causes, we will need some more information.I understand you're dealing with chronic gastric issues, neck and shoulder stiffness, and acid reflux. To provide the best advice, could you please tell me your age and gender?