Hi..
Welcome to HEALTHCARE MAGIC..
I have gone through your query and can understand your concerns..
As per your complain the symptoms are pointing towards 
acid reflux causing 
heartburn and redness in mouth and throat is due to acid causing chemical injury and inflammation..
You need to 
consult a Gastroenterologist and get evaluated and a thorough clinical evaluation and endoscopy can be diagnostic and he can advise you to take 
proton pump inhibitors like 
Omeprazole, take antacids half an hour before meals, take small frequent meals, avoid spicy and acidic foods, take short walk after meals, drink plenty of water and eat more of probiotics like Yoghurt, shed weight if obese and sleep with head and chest slightly raised as compared to feet..
If there is soreness and burning in mouth and throat gargle with numbing mouthwash containing Lignocaine and suck ice pops.
Drink plenty of cool water for relief from burning..
Hope this information helps..
Thanks and regards.
Dr. Honey Nandwani Arora.