That is virtually impossible to say without knowing your full medical history.
For instance , heart attacks are most common in early morning hours- do you have high blood pressure etc.
Indigestion is often caused by the H Pylori bacteria, and treated by antibiotics.
I think you should see a doctor for a physical exam.
It sounds like it is a good possibility to me. Them are just two of the symptoms for it. I would try two things. The first one would be to take an over the counter medicine like Zantac for example before you go to bed. If you are taking any other medication please ask your doctor or pharmacist if there would be any reaction between the two. The second thing I would try would be to try and sleep propped up some. Kind of like sleeping in a recliner. Hope this helps.