If I was you and its not getting better and its getting worse, I'd have it checked by a doctor. Its probably nothing, but its better to be safe than sorry.
Hi Shajanjose,
The red raised spots behind the tongue are the hypertrophied lingual tonsils, these are the lymphoid organs just like your tonsils. Do not worry much about it.
According to your history, you have mentioned that you are having acidity also. Hence its common in these individuals to have laryngo pharyngeal reflux. Please do consume plenty of warm water, avoid smoking (if any), alcohol (if any), spicy foods, coffee and tea for few days. Try proton pump inhibitors (such as Omeprazole/Esomeprazole). Any more doubts you are welcome.
Regards
OHNS2010