Your current regimen is a standard, safe, and effective approach for acute neck and shoulder pain. It combines an oral pain reliever and muscle relaxant with an antacid to protect your stomach, alongside a topical pain gel and heat therapy to relax the muscles. If you do not see improvement in the next 3 to 5 days, or if you experience numbness, tingling, or weakness radiating down your arm, please consult your doctor. They can evaluate you further, possibly recommending imaging like an X-ray or MRI, or suggesting physical therapy to aid your recovery.