The symptoms you have described are suggestive of a condition known as Gastro esophageal reflux Disease (GERD. It usually presents with Heartburn - which is a burning sensation extending from the stomach through the throat, regurgitation, nausea. These could be due to various causes such as Hiatus hernia, lower esophageal sphincter, and delayed stomach emptying.

The pain is usually consistent throughout the day and slightly lesser during the night. However, in certain individuals like you the pain is more during the night – nighttime GERD. This is because during the night the emptying of the stomach is much slower and this in turns leads to bloating of the stomach, which results in lower esophageal sphincter to relax causing acid reflux into the esophagus.

I would suggest a few remedies to reduce the acid reflux at night:

a) Avoid citric fruit, spicy food, alcohol, and caffeine and do not have consumed anything 3 hours before sleep.

b) While sleeping, it would be ideal if you sleep at an incline.

Try this for a week. It should get better.

If your symptoms are not reduced, then you can consult your doctor.