Thanks for your query.
First of all I would ask you not to panic.
You didnt mention your age and BMI. Are you obese
and have gained abdominal fat recently ?
May be your abdominal fat is causing you trouble by pressing the abdominal contents when you sleep on your stomach.It might also be the reason for your changed breathing pattern.
It is never advisable to overeat at night before sleeping and never sleep just after eating . Have a light easily digestable food at dinner and take some time after dinner before you go to sleep.It is not advisable to sleep prone on your stomach either.
If you are obese you need to decrease your body weight.Avoid too much of junk food and too much fatty foods.Do regular exercises and decrease your tummy fat.Regular situps will help.
If you have acidity then having proton pump
inhibitors an hour before food will help.
If you are having too much of problem then you must get a check up from your doctor.
Hope this helps.
Update here how you stay.